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1. Nano-plasmonic near field phase matching of attosecond pulses

Author

Tahir Shaaran, Rana Nicolas, Bianca Iwan, Milutin Kovacev, and Hamed Merdji

Subjects
Medicine, Science
Abstract

Abstract Nano-structures excited by light can enhance locally the electric field when tuned to plasmonic resonances. This phenomenon can be used to boost non-linear processes such as harmonic generation in crystals or in gases, Raman excitation, and four wave mixing. Here we present a theoretical investigation of the near-field phase matching of attosecond pulses emitted by high-order harmonic generation (HHG) of an atom immersed in a multi-cycle femtosecond infrared laser field and a spatially inhomogeneous plasmonic field. We demonstrate that the spatial inhomogeneity factor of the plasmonic field strongly affects the electron trajectory and recombination time which can be used to control the attosecond emission. For further insight into the plasmonic field effect, we monitor the phase of each quantum path as a function of the inhomogeneity strength. Moreover, we investigate the attosecond emission as a function of near-field phase matching effects. This is achieved by calculating the coherent field superposition of attosecond pulses emitted from various intensities or field inhomogeneities. Finally, far-field and near-field phase matching effects are combined to modulate the harmonic spectral phase towards the emission of a single attosecond pulse.

Published
2017
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2. Polarization spectroscopy of high-order harmonic generation in gallium arsenide

Author

Shatha Kaassamani, Thierry Auguste, Nicolas Tancogne-Dejean, Xu Liu, Willem Boutu, Hamed Merdji, David Gauthier, Dynamique et Interactions en phase Condensée (DICO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Max Rubner-Institut, Imagine Optic, and ANR-17-CE30-0008,PACHA,Harmoniques laser dans les cristaux assistées par la plasmonique(2017)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], FOS: Physical sciences, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], Atomic and Molecular Physics, and Optics, Physics - Optics, Optics (physics.optics)
Abstract

International audience; An interesting property of high harmonic generation in solids is its laser polarization dependent nature which in turn provides information about the crystal and band structure of the generation medium. Here we report on the linear polarization dependence of high-order harmonic generation from a gallium arsenide crystal. Interestingly, we observe a significant evolution of the anisotropic response of above bandgap harmonics as a function of the laser intensity. We attribute this change to fundamental microscopic effects of the emission process comprising a competition between intraband and interband dynamics. This intensity dependence of the anisotropic nature of the generation process offers the possibility to drive and control the electron current along preferred directions of the crystal, and could serve as a switching technique in an integrated all-solid-state petahertz optoelectronic device.

Published
2022

3. Self-probed ptychography from semiconductor high-harmonic generation

Author

Sven Fröhlich, Xu Liu, Aimrane Hamdou, Alric Meunier, Mukhtar Hussain, Mathieu Carole, Shatha Kaassamani, Marie Froidevaux, Laure Lavoute, Dmitry Gaponov, Nicolas Ducros, Sébastien Février, Philippe Zeitoun, Milutin Kovacev, Marta Fajardo, Willem Boutu, David Gauthier, Hamed Merdji, Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Dynamique et Interactions en phase Condensée (DICO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Imagine Optic, GoLP, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade Técnica de Lisboa-Instituto Superior Técnico, Universidade Técnica de Lisboa, Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Novae, XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Leibniz Universität Hannover=Leibniz University Hannover, ANR-17-CE30-0008,PACHA,Harmoniques laser dans les cristaux assistées par la plasmonique(2017), ANR-20-CE42-0013,FLEX-UV,Source à fibres optiques émettant dans l'ultraviolet extrême(2020), ANR-21-CE30-0036,ATTOCOM,Electronique attoseconde dans les semiconducteurs(2021), European Project: 665207,H2020,H2020-FETOPEN-2014-2015-RIA,VOXEL(2015), and European Project: 712590,H2020 FET Open 'Technologies futures et émergentes',829153,PETACom(2019)

Subjects
[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Physics::Optics, FOS: Physical sciences, Atomic and Molecular Physics, and Optics, Physics - Optics, Optics (physics.optics)
Abstract

We demonstrate a method to image an object using a self-probing approach based on semiconductor high-harmonic generation. On the one hand, ptychography enables high-resolution imaging from the coherent light diffracted by an object. On the other hand, high-harmonic generation from crystals is emerging as a new source of extreme-ultraviolet ultrafast coherent light. We combine these two techniques by performing ptychography measurements with nanopatterned crystals serving as the object as well as the generation medium of the harmonics. We demonstrate that this strong field in situ approach can provide structural information about an object. With the future developments of crystal high harmonics as a compact short-wavelength light source, our demonstration can be an innovative approach for nanoscale imaging of photonic and electronic devices in research and industry.

Published
2022

4. Manger ensemble et différemment : le halal, entre standardisation et segmentation

Author

Foued CHERIET, Félix JOURDAN, M’hamed MERDJI, SCHLEICH, Jean-Walter, and Gilles Séré de Lanauze

Subjects
Halal, France, [SHS.GESTION] Humanities and Social Sciences/Business administration
Abstract

Ce chapitre dresse un tableau des modes de production et de consommation de viande halal en France en s’interrogeant sur les dynamiques de différenciation et de standardisation de l’offre et les stratégies des acteurs. Les enjeux économiques, réglementaires et productifs sous-jacents à la « transformation » de l’animal et à la certification sont ensuite étudiés du point de vue de la demande et de son articulation avec l’offre.

Published
2022

5. High-Energy Solitonic Source of High Harmonics

Author

Yann Leventoux, Melek Jedidi, Lamine Ferhat, Cristian Jimenez, Idris Tiliouine, Geoffroy Granger, Jean-Christophe Orlianges, Aurelian Crunteanu, Laure Lavoute, Dmitry Gaponov, Johan Boullet, Marie Froidevaux, Willem Boutu, Hamed Merdji, Vincent Couderc, and Sebastien Fevrier

Abstract

We report on high harmonics generation in zinc oxide thin-films driven by an all-solid fiber-based architecture. The laser delivers 41 nJ 70 fs solitonic pulses at 1764 nm and drives harmonics generation up to H7.

Published
2022

6. Eating together and differently: Halal between standardization and segmentation

Author

Foued Cheriet, Félix Jourdan, M'hamed Merdji, Montpellier Interdisciplinary center on Sustainable Agri-food systems (Social and nutritional sciences) (UMR MoISA), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Centre International de Hautes Etudes Agronomiques Méditerranéennes - Institut Agronomique Méditerranéen de Montpellier (CIHEAM-IAMM), Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM)-Centre International de Hautes Études Agronomiques Méditerranéennes (CIHEAM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Innovation et Développement dans l'Agriculture et l'Alimentation (UMR Innovation), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Groupe Sup de Co Montpellier (GSCM) - Montpellier Business School, and Gilles Séré de Lanauze

Subjects
marketing, Halal, [SHS.GESTION]Humanities and Social Sciences/Business administration, France
Abstract

International audience; This chapter looks at the concepts of “eating together” and “eating differently” in the halal meat market through the dynamics of standardization versus differentiation, both in terms of purchasing practices and offers, as well as in terms of meat production methods and guarantees of their halal nature. The halal market illustrates the problem of eating together AND differently and reflects the coexistence of these two strategic dynamics of standardization-differentiation of offer, responding to an increasingly complex demand. The study of the phenomena of standardization-segmentation will shed light on the economic, regulatory and productive issues underlying the “transformation” of the living animal into a halal meat product identifiable by consumers. The chapter also examines the main specificities of halal meat consumption. Some trends are consistent with what is generally observed in food supply and demand practices; others are more specific to the halal meat market.

Published
2021

7. Enhanced extreme ultraviolet high-harmonic generation from chromium-doped magnesium oxide

Author

Willem Boutu, A. Hamdou, Viktoria Nefedova, Francisco Navarrete, Nicolas Tancogne-Dejean, Uwe Thumm, Patrick Georges, Gaëtan Jargot, Dominik Franz, Shatha Kaassamani, Hamed Merdji, Sven Fröhlich, Rana Nicolas, Marc Hanna, Marcelo F. Ciappina, D. Gauthier, Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Kansas State University, Institut für Physik [Rostock], Universität Rostock, Max Planck Institute for the Structure and Dynamics of Matter (MPSD), Laboratoire Charles Fabry / Lasers, Laboratoire Charles Fabry (LCF), Institut d'Optique Graduate School (IOGS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Barcelona Institute of Science and Technology (BIST), ANR-17-CE30-0008,PACHA,Harmoniques laser dans les cristaux assistées par la plasmonique(2017), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Semiconductor Bloch equations, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Physics and Astronomy (miscellaneous), Doping, Physics::Optics, 02 engineering and technology, 021001 nanoscience & nanotechnology, Laser, 01 natural sciences, Molecular physics, law.invention, Crystal, Condensed Matter::Materials Science, law, Vacancy defect, Extreme ultraviolet, Condensed Matter::Superconductivity, 0103 physical sciences, Physics::Atomic and Molecular Clusters, High harmonic generation, 0210 nano-technology, Anisotropy
Abstract

International audience; High-order harmonic generation (HHG) from crystals is emerging as a new ultrashort source of coherent extreme ultraviolet (XUV) light. Doping the crystal structure can offer a new way to control the source properties. Here, we present a study of HHG enhancement in the XUV spectral region from an ionic crystal, using dopant-induced vacancy defects, driven by a laser centered at a wavelength of 1.55 lm. Our numerical simulations based on solutions of the semiconductor Bloch equations and density-functional theory are supported by our experimental observations and demonstrate an increase in the XUV high harmonic yield from doped bulk magnesium oxide (MgO) compared to undoped MgO, even at a low defect concentration. The anisotropy of the harmonic emission as a function of the laser polarization shows that the pristine crystal's symmetry is preserved. Our study paves the way toward the control of HHG in solids with complex defects caused by transition-metal doping.

Published
2021

8. Single-shot spatial coherence characterization of x-ray ultrafast sources

Author

Maria Kholodstova, Marta Fajardo, Rana Nicolas, Joana Duarte, Rémy Cassin, Hamed Merdji, Willem Boutu, A. I. Gonzalez, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Plasmas e Fusão Nuclear [Lisboa] (IPFN), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Image formation, Physics, [PHYS]Physics [physics], business.industry, Near and far field, 02 engineering and technology, 021001 nanoscience & nanotechnology, Interference (wave propagation), 01 natural sciences, Atomic and Molecular Physics, and Optics, Ptychography, Metrology, Characterization (materials science), 010309 optics, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], Optics, Robustness (computer science), 0103 physical sciences, 0210 nano-technology, business, Ultrashort pulse
Abstract

Spatial coherence is an impactful source parameter in many applications ranging from atomic and molecular physics to metrology or imaging. In lensless imaging, for example, it can strongly affect the image formation, especially when the source exhibits shot-to-shot variations. Single-shot characterization of the spatial coherence length of a source is thus crucial. However, current techniques require either parallel intensity measurements or the use of several masks. Based on the method proposed by González et al. [J. Opt. Soc. Am. A 28, 1107 (2011)JOAOD60740-323210.1364/JOSAA.28.001107], we designed a specific arrangement of a two-dimensional non-redundant array of apertures, which allows, through its far field interference pattern, for a single-shot measurement of the spatial coherence, while being robust against beam-pointing instabilities. The strategic configuration of the pinholes allows us to disentangle the degree of spatial coherence from the intensity distribution, thus removing the need for parallel measurement of the beam intensity. An experimental validation is performed using a high-harmonic source. A statistical study in different regimes shows the robustness of the method.

Published
2021

9. Spectral control of high order harmonics through non-linear propagation effects

Author

Gareth O. Williams, Rana Nicolas, Willem Boutu, Sébastien Février, L. Lavoute, Shatha Kaassamani, Marta Fajardo, Tayyab Imran, Maria Kholodtsova, Hamed Merdji, Mukhtar Hussain, Thierry Auguste, D. Gaponov, P. Zeitoun, Jean-Thomas Gomes, Nicolas Ducros, D. Gauthier, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Novae, Department of Natural Sciences [Lebanese American University] (NS/SAS/LAU), School of Arts and Sciences [Lebanese American University] (SAS/LAU), Lebanese American University (LAU)-Lebanese American University (LAU), Syed Babar Ali School of Science and Engineering, Lahore University of Management Sciences (LUMS), Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centro de Fisica de Plasmas (GoLP), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Physics and Astronomy (miscellaneous), business.industry, Attosecond, FOS: Physical sciences, 01 natural sciences, Spectral line, Blueshift, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], 010309 optics, Harmonic spectrum, Wavelength, Optics, Harmonics, 0103 physical sciences, Physics::Atomic and Molecular Clusters, High harmonic generation, [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph], 010306 general physics, business, Ultrashort pulse, Physics - Optics, Optics (physics.optics)
Abstract

High harmonic generation (HHG) in crystals has revealed a wealth of perspectives such as all-optical mapping of the electronic band structure, ultrafast quantum information and the creation of novel all-solid-state attosecond sources. Significant efforts have been made to understand the microscopic aspects of HHG in crystals, whereas the macroscopic effects, such as non-linear propagation effects of the driving pulse inside the dense solid media and its impact on the HHG process is often overlooked. In this work, we study macroscopic effects by comparing two materials with distinct optical properties, silicon (Si) and zinc oxide (ZnO). By scanning the focal position of 85 fs, 2.123 $\mu$m wavelength pulses inside the crystals (Z-scan) we reveal spectral shifts in the generated harmonics. We interpret the overall blueshift of the emitted harmonic spectrum as an imprint of the driving field spectral modulation occurring during the propagation inside the crystal. This is supported with numerical simulations. This study demonstrates that through manipulation of the fundamental driving field through non-linear propagation effects, precise control of the emitted HHG spectrum in solids can be realised. This method could offer a robust way to tailor HHG spectra for a range of spectroscopic applications., Comment: 6 pages,6 figures

Published
2021
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10. High Harmonics and Isolated Attosecond Pulses from MgO

Author

Zahra Nourbakhsh, Angel Rubio, Nicolas Tancogne-Dejean, Hamed Merdji, European Commission, Max Planck Institute for the Structure and Dynamics of Matter (MPSD), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Center for Computational Quantum Physics, The Flatiron Institute, 162 Fifth Avenue, New York 10010, USA, ANR-10-LABX-0039,PALM,Physics: Atoms, Light, Matter(2010), European Project: 694097,QSpec-NewMat, European Project: 712590,H2020 FET Open 'Technologies futures et émergentes',829153,PETACom(2019), and European Project: 899794,OPTOlogic

Subjects
Attosecond, General Physics and Astronomy, Physics::Optics, FOS: Physical sciences, 02 engineering and technology, Radiation, 01 natural sciences, law.invention, Crystal, Ab initio quantum chemistry methods, law, generation, 0103 physical sciences, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, 010306 general physics, Crystal anisotropy, Physics, [PHYS]Physics [physics], Condensed Matter - Materials Science, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Laser, radiation, Harmonics, Atomic physics, 0210 nano-technology, Intensity (heat transfer), Physics - Optics, Optics (physics.optics)
Abstract

On the basis of real-time ab initio calculations, we study the nonperturbative interaction of two-color laser pulses with MgO crystal in the strong-field regime to generate isolated attosecond pulses from high-harmonic emissions from MgO crystal. In this regard, we examine the impact of the characteristics of the incident pules, such as its shape, intensity, and ellipticity, as well as the consequences of the crystal anisotropy on the emitted harmonics and their corresponding isolated attosecond pulses. Our calculations predict the creation of isolated attosecond pulses with a duration of approximately 300 as; in addition, using elliptical driving pulses, we show the generation of elliptical isolated attosecond pulses. Our work prepares the path for all-solid-state compact optical devices offering perspectives beyond traditional isolated attosecond pulses emitted from atoms. This work was supported by the European Research Council (Grant No. ERC-2015-AdG694097), the Deutsche Forschungsgemeinschaft through the Priority Programme Quantum Dynamics in Tailored Intense Fields, Grupos Consolidados (Grant No. IT1249-19), the Cluster of Excellence Advanced Imaging of Matter, and the Max Planck -New York City Center for Non-Equilibrium Quantum Phenomena. The Flatiron Institute, which is a division of the Simons Foundation, is acknowledged. H.M. acknowledges support from PETACom FET Open Horizon 2020 (Grant No. 829153), OPTOLogic FET Open Horizon 2020 (Grant No. 899794), DGA RAPID grant "SWIM," the C'NANO research program through a NanoscopiX grant, and LABEX "PALM" (ANR-100LABX-0039-PALM) through grants "Plasmon-X" and "STAMPS." We acknowledge financial support from the French ASTRE program through the grant "NanoLight." Fruitful discussion with O.D. Mucke is acknowledged.

Published
2021

11. Optique attoseconde et électronique pétahertz dans les semiconducteurs

Author

Hamed Merdji, Willem Boutu, Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 3. Good health
Abstract

International audience; La génération d’harmoniques laser d’ordre élevé dans les cristaux semiconducteurs est une nouvelle source de rayonnement ultra-bref (femtoseconde à attoseconde) cohérent et de courte longueur d’onde (de l’ordre de quelques dizaines de nanomètres) à très haute cadence. Outre la versatilité de cette source pour les applications, offerte notamment par les progrès en nano-structuration, l’étude du rayonnement émis permet de suivre les dynamiques électroniques ultrarapides au sein de matériaux complexes.

Published
2021

12. Subthreshold Erosion of an Organic Polymer Induced by Multiple Shots of an X-Ray Free-Electron Laser

Author

Jaromír Chalupský, Stefan P. Hau-Riege, Svea Kreis, Jacek Krzywinski, M. Toufarová, A. Graf, Marc Messerschmidt, Stefan Moeller, Věra Hájková, Thierry Auguste, K. Tiedtke, Christoph Bostedt, Ryszard Sobierajski, S. Guizard, John D. Bozek, Hamed Merdji, Libor Juha, B. Carré, U. Jastrow, M. De Grazia, Tomáš Burian, Vladimír Vorlíček, Nikita Medvedev, Richard A. London, Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Biomolécules Excitées (DICO), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Dynamique et Interactions en phase Condensée (DICO)

Subjects
[PHYS]Physics [physics], Materials science, Photon, Free-electron laser, General Physics and Astronomy, Synchrotron radiation, 02 engineering and technology, Photon energy, Radiation, 021001 nanoscience & nanotechnology, 01 natural sciences, Fluence, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], Extreme ultraviolet, 0103 physical sciences, ddc:530, Irradiation, Atomic physics, 010306 general physics, 0210 nano-technology
Abstract

Physical review applied 14(3), 034057 (2020). doi:10.1103/PhysRevApplied.14.034057, Solids irradiated by energetic photons can be eroded in two modes, depending on the radiation intensity. High average, low-peak power sources, e.g., synchrotron radiation and high-order harmonics, induce desorption of the material at a low etch rate. In contrast, high-peak-power radiation from extreme ultraviolet and x-ray lasers usually causes a massive removal of the material even by a single shot. In this contribution, an effective material erosion is reported in PMMA exposed to multiple accumulated pulses generated by the free-electron x-ray-laser Linac Coherent Light Source (LCLS, tuned at a photon energy of 830 eV in this study, operated in Menlo Park at Stanford, CA, USA) at a fluence below the single-pulse ablation threshold. The effect is caused by polymer-chain scissions initiated by single photons carrying enough energy to break the C$—$C bounds. High efficiency of the erosion is supposed to occur due to a correlation of the single-photon effects. The subthreshold damage exhibits a nonlinear dose dependence resulting from a competition between chain scissions and cross-linking processes. The cross-linking is proven by Raman spectroscopy of the irradiated polymer. Two theoretical models of the x-ray free-electron-laser-induced erosion are suggested, which provide an excellent agreement with the experimental results., Published by American Physical Society, College Park, Md. [u.a.]

Published
2020

13. Author Correction: All semiconductor enhanced high-harmonic generation from a single nanostructured cone

Author

Shatha Kaassamani, Hamed Merdji, Jens Biegert, Jean-Thomas Gomes, Ludovic Douillard, Rana Nicolas, Maria Kholodtsova, Dmitry Gaponov, Nicolas Ducros, D. Gauthier, Dominik Franz, Laure Lavoute, Liping Shi, Milutin Kovacev, Willem Boutu, and Sébastien Février

Subjects
Physics, 0303 health sciences, Multidisciplinary, business.industry, lcsh:R, lcsh:Medicine, Cone (formal languages), 03 medical and health sciences, 0302 clinical medicine, Optics, Semiconductor, 030220 oncology & carcinogenesis, High harmonic generation, lcsh:Q, lcsh:Science, business, 030304 developmental biology
Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2020

15. Controlling the non-linear optical properties of MgO by tailoring the electronic structure

Author

Gareth O. Williams, Rana Nicolas, Hamed Merdji, Marta Fajardo, Tayyab Imran, Willem Boutu, Dominik Franz, Hugo Pires, Mukhtar Hussain, Centro de Fisica de Plasmas (GoLP), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics, COMSATS Institute of Information Technology (COMSATS), COMSATS, COMSATS Institute of Information Technology [Islamabad] (CIIT), ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Physics and Astronomy (miscellaneous), General Physics and Astronomy, FOS: Physical sciences, Physics::Optics, Electronic structure, Electron, 01 natural sciences, 010309 optics, Condensed Matter::Materials Science, Electric field, 0103 physical sciences, Physics::Atomic and Molecular Clusters, High harmonic generation, [NLIN]Nonlinear Sciences [physics], 010306 general physics, Dopant, business.industry, Doping, General Engineering, Second-harmonic generation, Optoelectronics, Density functional theory, business, Optics (physics.optics), Physics - Optics
Abstract

The study of the non-linear response of matter to high electric fields has recently encompassed harmonic generation in solids at near-infrared (NIR) driving wavelengths. Interest has been driven by the prospect of ultrafast signal processing and all-optical mapping of electron wave-functions in solids. Engineering solid-state band structures to control the non-linear process has already been highlighted theoretically. Here, we show experimentally for the first time that second harmonic generation (SHG) can be enhanced by doping crystals of magnesium oxide (MgO) with chromium (Cr) atoms. We show that the degree of enhancement depends non-linearly on dopant concentration. The SHG efficiency is shown to increase when Cr dopants are introduced into pure MgO. A physical picture of the effect of Cr dopants is aided by density functional theory (DFT) calculations of the electronic structure for pure and doped samples. This work shows an unambiguous enhancement of the SHG efficiency by modifying the electronic structure. The observed effects are consistent with an electronic structure that facilitates the surface induced SHG and demonstrates a minimal angular dependence. This work highlights the potential of manipulating the electronic structure of solids to control or test theories of their non-linear optical response., We have some technical and scientific issues in this article which need to be corrected

Published
2020

16. Towards complete band structure of microscopic MoS2 flakes

Author

Sergey Babenkov, Marie Froidevaux, Peng Ye, Ludovic Tortech, Yannick Dappe, Willem Boutu, Nickolas Barrett, and Hamed Merdji

Abstract

The occupied and unoccupied electronic states of MoS2 monolayer isolated flake were studied using laboratory based photoemission electron microscope (PEEM) nanoESCA equipped with He-I photon source. PEEM real-space imaging allowed selecting the high quality flake. Altogether, the data will allow accurately recovering the band structures of MoS2. The band structures will be used in future pump-probe experiments to explore the dynamics of electrons in the conduction band and photo-induced multitopological states using trefoil polarization.

Published
2022

17. Lensless microscopy platform for single cell and tissue visualization

Author

Maria Kholodtsova, Fabrice Harms, Laure Bally-Cuif, Hamed Merdji, Joana Duarte, Samuel Bucourt, Nicolas Dray, Anna Campalans, Ramona Corman, Pablo Radicella, Guillaume Dovillaire, Willem Boutu, Imagine Optic, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Radiobiologie Cellulaire et Moléculaire (IRCM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Neurogénétique du Poisson zébré / Zebrafish Neurogenetics, Institut Pasteur [Paris] (IP)-Centre National de la Recherche Scientifique (CNRS), We acknowledge support from the CEA/DRF Impulsion program with the grant 'NanoBiom', Défi 'IMAG’IN' CNRS grant program 'Nano-bio-4D. We acknowledge support from Région Ile de France through the DIM ELICIT program, grant IMAChip and the Action de Soutien à la Technologie et à la Recherche en Essonne (ASTRE) program through the 'NanoLight' project. We acknowledge financial support from the European Union through the Future and Emerging Technologies (FET) Open H2020: VOXEL (grant 665207) and PETACom (grant 829153) and the integrated initiative of European laser research infrastructure (LASERLAB-EUROPE) (grant agreement no. 654148). Support from the French ministry of research through the 2013 Agence Nationale de Recherche (ANR) grants 'NanoImagine', 2014 'ultrafast lensless Imaging with Plasmonic Enhanced Xuv generation (IPEX)', 2016 'High rEpetition rate Laser for Lensless Imaging in the Xuv (HELLIX)', from the DGA RAPID grant 'SWIM', from the Centre National de Compétences en Nanosciences (C'NANO) research program through the NanoscopiX grant, the LABoratoire d'EXcelence Physique Atoms Lumière Matière -LABEX PALM (ANR-10-LABX-0039-PALM), through the grants 'Plasmon-X' and 'HIgh repetition rate Laser hArmonics in Crystals (HILAC)' are acknowledged, ANR-13-NANO-0005,NanoImagine,Imagerie Nanométrique Sans Lentille par diffraction(2013), ANR-14-CE35-0020,IPEX,Ultrafast lensless imaging with plasmonic enhanced XUV generation(2014), ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016), ANR-11-IDEX-0003,IPS,Idex Paris-Saclay(2011), European Project: 665207,H2020,H2020-FETOPEN-2014-2015-RIA,VOXEL(2015), European Project: 712590,H2020 FET Open 'Technologies futures et émergentes',829153,PETACom(2019), European Project: 654148,H2020,H2020-INFRAIA-2014-2015,LASERLAB-EUROPE(2015), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Instituto de Plasmas e Fusão Nuclear [Lisboa] (IPFN), Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Département de Biologie du Développement et Cellules souches - Department of Developmental and Stem Cell Biology, Institut Pasteur [Paris], Cellules Souches et Développement, Institut Pasteur [Paris]-Centre National de la Recherche Scientifique (CNRS), Institut Langevin ondes et images, and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-ESPCI ParisTech-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], 0303 health sciences, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], business.industry, Computer science, 01 natural sciences, Atomic and Molecular Physics, and Optics, Article, Visualization, 010309 optics, 03 medical and health sciences, Three dimensional imaging, 3d image, 0103 physical sciences, Microscopy, Computer vision, Artificial intelligence, [NLIN]Nonlinear Sciences [physics], business, Image resolution, 030304 developmental biology, Biotechnology
Abstract

Today, 3D imaging techniques are emerging, not only as a new tool in early drug discovery but also for the development of potential therapeutics to treat disease. Particular efforts are directed towards in vivo physiology to avoid perturbing the system under study. Here, we assess non-invasive 3D lensless imaging and its impact on cell behavior and analysis. We test our concept on various bio-applications and present here the first results. The microscopy platform based on in-holography provides large fields of view images (several mm2 compared to several hundred µm2) with sub-micrometer spatial resolution. 3D image reconstructions are achieved using back propagation functions post-processing.

Published
2019

18. Generating Ultrabroadband Deep-UV Radiation and Sub-10 nm Gap by Hybrid-Morphology Gold Antennas

Author

Hamed Merdji, Bert Bastiaens, Juemin Yi, T. Heidenblut, Maria Kholodtsova, Ihar Babushkin, Frans B. Segerink, Ayhan Tajalli, Jiao Geng, Liping Shi, Jose R. C. Andrade, Uwe Morgner, Milutin Kovacev, Institut für Quantenoptik [Hannover] (IQ), Leibniz Universität Hannover [Hannover] (LUH), Center of Interface Science [Oldenburg], University of Oldenburg, Optical Sciences, MESA+ Institute for Nanotechnology, University of Twente, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute for Nanotechnology (MESA+), University of Twente [Netherlands], European Project: 712590,H2020 FET Open 'Technologies futures et émergentes',829153,PETACom(2019), Leibniz Universität Hannover=Leibniz University Hannover, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Twente, Optical Sciences, and Laser Physics & Nonlinear Optics

Subjects
Materials science, Physics::Optics, Bioengineering, 02 engineering and technology, Optical field, law.invention, Near-field mapping, Optics, law, General Materials Science, Plasmonic lens, Center frequency, Plasmon, Laser ablation, business.industry, Mechanical Engineering, General Chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Laser, Nanoscale gaps, 22/4 OA procedure, Photon upconversion, Wavelength, Nonlinear plasmonics, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Broadband deep-ultraviolet, 0210 nano-technology, business
Abstract

International audience; We experimentally investigate the interaction between hybrid-morphology gold optical antennas and a few-cycle Ti:sapphire laser up to ablative intensities, demonstrating rich nonlinear plasmonic effects and promising applications in coherent frequency upconversion and nanofabrication technology. The two-dimensional array of hybrid antennas consists of elliptical apertures combined with bowties in its minor axis. The plasmonic resonance frequency of the bowties is red-shifted with respect to the laser central frequency and thus mainly enhances the third harmonic spectrum at long wavelengths. The gold film between two neighboring elliptical apertures forms an hourglass-shaped structure, which acts as a “plasmonic lens” and thus strongly reinforces surface currents into a small area. This enhanced surface current produces a rotating magnetic field that deeply penetrates into the substrate. At resonant frequency, the magnetic field is further intensified by the bowties. The resonant frequency of the hourglass is blueshifted with respect to the laser central frequency. Consequently, it spectacularly extends the third harmonic spectrum toward short wavelengths. The resultant third harmonic signal ranges from 230 to 300 nm, much broader than the emission from a sapphire crystal. In addition, the concentration of surface current within the neck of the hourglass antenna results in a structural modification through laser ablation, producing sub-10 nm sharp metallic gaps. Moreover, after laser illumination the optical field hotspots are imprinted around the antennas, allowing us to confirm the subwavelength enhancement of the electric near-field intensity.

Published
2019

19. CEP-Stable 100 kHz Nonlinearly Compressed YDFA Source for HHG

Author

Loic Lavenu, W. Bouta, J.-F. Hergott, Florent Guichard, Marc Hanna, Michele Natile, X. Chen, Hamed Merdji, Y. Zaouter, R. Chiche, Patrick Georges, Laboratoire Charles Fabry (LCF), Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016)

Subjects
ultra-high efficiency nonlinear compression, laser repetition rate, nonlinear compression scheme, 02 engineering and technology, 01 natural sciences, law.invention, Fiber lasers, laser stability, CEP-stable nonlinearly compressed YDFA source, law, Optical fiber amplifiers, High harmonic generation, reduced acquisition time, bandwidth 100.0 kHz, HHG-related applications, Physics, optical pulse generation, [PHYS]Physics [physics], ytterbium, 021001 nanoscience & nanotechnology, HHG photon flux, optical pulse compression, signal-to-noise ratio, 0210 nano-technology, Noise measurement, low-interaction probability experiments, Phase (waves), optical fibre amplifiers, Frequency conversion, ytterbium-doped amplifiers, 010309 optics, Optics, 0103 physical sciences, Optimized production technology, Laser theory, improved statistics, business.industry, Amplifier, light sources, Photon flux, ytterbium-doped fiber amplifiers, carrier-envelope phase stabilization, Laser, high harmonic generation, Nonlinear system, optical harmonic generation, Photonics, Fiber amplifier, Acquisition time, business
Abstract

International audience; Summary form only given. Over the last years, the interest for high repetition rate (>100kHz) sources used for high harmonic generation (HHG) has been growing up widely. Indeed, increasing laser repetition rate allows, for example, to drastically increase the HHG photon flux. Moreover, additional benefits such as improved statistics and signal-to-noise ratio or a reduced acquisition time are also paramount for low-interaction probability experiments. Using nonlinear compression scheme, Yb-doped fiber amplifiers (YDFA) are now able to provide the performances suitable for HHG-related applications. However, one of the remaining bottleneck of these sources is the lack of carrier-envelope phase (CEP) stabilization. So far, CEP stabilization of ytterbium-doped amplifiers has only been demonstrated for oscillator or low energy systems. We have demonstrated a high energy FCPA operated at 100 kHz showing excellent CEP stability. We believe that power and energy scaling toward > 100 W, > lmJ, with CEP -stabilization is within reach. Together with recently demonstrated ultra -high efficiency nonlinear compression to few cycle pulse duration [6], this new kind of source promises to disrupt applications in attoscience.

Published
2019

20. All-Fiber System at 1750 nm Delivering 35 fs 230 kW Peak Power Pulses

Author

Dominik Franz, Sébastien Février, Hamed Merdji, G. Granger, Hugo Delahaye, Photonique Fibre et Sources Cohérentes (XLIM-PHOT), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE08-0031,BISCOT,Sources à supercontinuum large bande dans le moyen infra-rouge(2016), and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, Optical fiber, business.industry, Physics::Optics, Soliton (optics), 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Metrology, Power (physics), 010309 optics, All fiber, law, 0103 physical sciences, Harmonic, High harmonic generation, Optoelectronics, 0210 nano-technology, business, Lasing threshold
Abstract

International audience; Ultra-short (1.55 μm) are very attractive for many applications such as three-photon microscopy, frequency metrology, or high harmonic generation. Solitonic self-compression is an attractive effect for this purpose as compression to sub-50 fs pulses can be achieved without the need for external compressing optics, directly out of an optical fiber. Self-compression at high energy was demonstrated around 2 μm in all-solid or gas-filled hollow-core-PCFs. However, the latter demonstrations were restricted to Tm emission band in order to reach the soliton self-compression effect in low-nonlinearity media. In this communication, we present a compact monolithic all-fiber source of ultrashort (35 fs) pulses emitting outside conventional lasing bands, from 1.65 to 2 μm based on Raman-induced soliton self-frequency shift (SSFS) and soliton self-compression (SSC)

Published
2019

21. All semiconductor enhanced high-harmonic generation from a single nanostructured cone

Author

Liping Shi, Jean-Thomas Gomes, Milutin Kovacev, Ludovic Douillard, Dmitry Gaponov, Shatha Kaassamani, D. Gauthier, Laure Lavoute, Willem Boutu, Nicolas Ducros, Jens Biegert, Hamed Merdji, Rana Nicolas, Dominik Franz, Sébastien Février, Maria Kholodtsova, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Electronique et nanoPhotonique Organique (LEPO), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Novae, Photonique Fibre et Sources Cohérentes (XLIM-PHOT), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Institut de Ciencies Fotoniques [Castelldefels] (ICFO), Institut für Quantenoptik [Hannover] (IQ), Leibniz Universität Hannover=Leibniz University Hannover, C'NANO research program through the NanoscopiX grant, LABEX 'PALM' through grants 'Plasmon-X', 'STAMPS', 'HILAC', French ASTRE program through the 'NanoLight' grant, Conseil Regional de Nouvelle-Aquitaine grant 2017 'FLOWA', DGA RAPID grant 'SWIM', ANR-11-IDEX-0003,IPS,Idex Paris-Saclay(2011), ANR-14-CE35-0020,IPEX,Ultrafast lensless imaging with plasmonic enhanced XUV generation(2014), ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016), ANR-16-CE08-0031,BISCOT,Sources à supercontinuum large bande dans le moyen infra-rouge(2016), ANR-10-LABX-0039,PALM,Physics: Atoms, Light, Matter(2010), European Project: 712590,H2020 FET Open 'Technologies futures et émergentes',829153,PETACom(2019), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Leibniz Universität Hannover [Hannover] (LUH)

Subjects
0301 basic medicine, Materials science, Extreme ultraviolet lithography, lcsh:Medicine, 7. Clean energy, Article, law.invention, 03 medical and health sciences, 0302 clinical medicine, law, High harmonic generation, Author Correction, lcsh:Science, [PHYS]Physics [physics], Multidisciplinary, business.industry, lcsh:R, Metamaterial, Laser, 030104 developmental biology, Semiconductor, Harmonics, Femtosecond, Harmonic, Optoelectronics, lcsh:Q, business, 030217 neurology & neurosurgery
Abstract

The enhancement and control of non-linear phenomena at a nanometer scale has a wide range of applications in science and in industry. Among these phenomena, high-harmonic generation in solids is a recent focus of research to realize next generation petahertz optoelectronic devices or compact all solid state EUV sources. Here, we report on the realization of the first nanoscale high harmonic source. The strong field regime is reached by confining the electric field from a few nanojoules femtosecond laser in a single 3D semiconductor waveguide. We reveal a strong competition between enhancement of coherent harmonics and incoherent fluorescence favored by excitonic processes. However, far from the band edge, clear enhancement of the harmonic emission is reported with a robust sustainability offering a compact nanosource for applications. We illustrate the potential of our harmonic nano-device by performing a coherent diffractive imaging experiment. Ultra-compact UV/X-ray nanoprobes are foreseen to have other applications such as petahertz electronics, nano-tomography or nano-medicine.

Published
2019

22. Computed stereo lensless X-ray imaging

Author

R. Cassin, Hamed Merdji, Julius Huijts, Milutin Kovacev, Marta Fajardo, F. Fortuna, Henry N. Chapman, Bianca Iwan, Willem Boutu, Joana Duarte, L. Delbecq, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Department of Earth Sciences [Cambridge, UK], University of Cambridge [UK] (CAM), Instituto de Telecomunicações [Lisboa, Portugal], Leibniz Universität Hannover [Hannover] (LUH), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Leibniz Universität Hannover=Leibniz University Hannover, and ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016)

Subjects
Diffraction, Computer science, Machine vision, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, 010309 optics, 0103 physical sciences, FOS: Electrical engineering, electronic engineering, information engineering, Computer vision, ddc:530, Pyramid (image processing), Representation (mathematics), ComputingMethodologies_COMPUTERGRAPHICS, [PHYS]Physics [physics], business.industry, Image and Video Processing (eess.IV), Robotics, Electrical Engineering and Systems Science - Image and Video Processing, 021001 nanoscience & nanotechnology, Sample (graphics), Atomic and Molecular Physics, and Optics, 3. Good health, Electronic, Optical and Magnetic Materials, Stereopsis, A priori and a posteriori, Artificial intelligence, 0210 nano-technology, business, Optics (physics.optics), Physics - Optics
Abstract

Recovering the three-dimensional (3D) properties of artificial or biological systems using low X-ray doses is challenging as most techniques are based on computing hundreds of two-dimensional (2D) projections. The requirement for a low X-ray dose also prevents single-shot 3D imaging using ultrafast X-ray sources. Here we show that computed stereo vision concepts can be applied to X-rays. Stereo vision is important in the field of machine vision and robotics. We reconstruct two X-ray stereo views from coherent diffraction patterns and compute a nanoscale 3D representation of the sample from disparity maps. Similarly to brain perception, computed stereo vision algorithms use constraints. We demonstrate that phase-contrast images relax the disparity constraints, allowing occulted features to be revealed. We also show that by using nanoparticles as labels we can extend the applicability of the technique to complex samples. Computed stereo X-ray imaging will find application at X-ray free-electron lasers, synchrotrons and laser-based sources, and in industrial and medical 3D diagnosis methods. Stereo images of gold nanoparticles in a pyramid shape are reconstructed from X-ray coherent diffraction patterns. Depth information is retrieved by computing disparity maps without a priori knowledge of the sample shape.

Published
2019

23. Impact of free electron degeneracy on collisional rates in plasmas

Author

Gareth O. Williams, V. Hilbert, Marta Fajardo, S. Künzel, Bianca Iwan, B. Barbrel, P. Zeitoun, Willem Boutu, A. I. Gonzalez, Eduardo Granados, Philip Heimann, Byoung-ick Cho, S. Daboussi, Howard A. Scott, Ulf Zastrau, Eric Galtier, Richard W. Lee, Bob Nagler, Hae Ja Lee, Hamed Merdji, Hyun-Kyung Chung, P. Renaudin, and Publica

Subjects
Free electron model, Physics, Code (set theory), Degenerate energy levels, FOS: Physical sciences, Plasma, 01 natural sciences, Measure (mathematics), Physics - Plasma Physics, 010305 fluids & plasmas, Plasma Physics (physics.plasm-ph), Physics::Plasma Physics, Quantum electrodynamics, 0103 physical sciences, Degeneracy (biology), 010306 general physics, Computer Science::Databases
Abstract

Degenerate plasmas, in which quantum effects dictate the behavior of free electrons, are ubiquitous on earth and throughout space. Transitions between bound and free electron states determine basic plasma properties, yet the effects of degeneracy on these transitions have only been theorized. Here, we use an x-ray free electron laser to create and characterize a degenerate plasma. We observe a core electron fluorescence spectrum that cannot be reproduced by models that ignore free electron degeneracy. We show that degeneracy acts to restrict the available electron energy states, thereby slowing the rate of transitions to and from the continuum. We couple degeneracy and bound electron dynamics in an existing collisional-radiative code, which agrees well with observations. The impact of the shape of the cross section, and hence the magnitude of the correction due to degeneracy, is also discussed. This study shows that degeneracy in plasmas can significantly influence experimental observables such as the emission spectra, and that these effects can be included parametrically in well-established atomic physics codes. This work narrows the gap in understanding between the condensed-matter and plasma phases, which coexist in myriad scenarios.

Published
2019
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24. Amplification of high-order harmonics in semiconductor waveguides

Author

Dominik Franz, Shatha Kaassamani, David Gauthier, Rana Nicolas, Willem Boutu, Jean-Thomas Gomes, Laure Lavoute, Dmitry Gaponov, Nicolas Ducros, Sébastien Fevrier, Hamed Merdji, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Novae, Photonique Fibre et Sources Cohérentes (XLIM-PHOT), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Jamier, Raphael, and Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-OPTICS] Physics [physics]/Physics [physics]/Optics [physics.optics], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2018

25. Amplification of solid high harmonics in semiconductor nanostructures (Conference Presentation)

Author

Milutin Kovacev, Ugaitz Elu Etxano, Jens Biegert, Dominik Franz, Quentin Ripault, Rana Nicolas, Maria Kholodtsova, Bianca Iwan, Hamed Merdji, Willem Boutu, and Liping Shi

Subjects
Nanostructure, Materials science, business.industry, Orders of magnitude (temperature), Physics::Optics, Laser, law.invention, Semiconductor, law, Harmonics, Harmonic, High harmonic generation, Optoelectronics, business, Plasmon
Abstract

Nanoscale amplification of non-linear processes in solid-state devices opens novel applications in nano-electronics, nano-medicine or high energy conversion for example. Coupling few nano-joules laser energy at a nanometer scale for strong field physics is demonstrated. We report enhancement of high harmonic generation in nano-structured semiconductors using nanoscale amplification of a mid-infrared laser in the sample rather than using large laser amplifier systems. Field amplification is achieved through light confinement in nano-structured semiconductor 3D waveguides. The high harmonic nano-converter consists of an array of zinc-oxide nanocones. They exhibit a large amplification volume, 6 orders of magnitude larger than previously reported [1] and avoid melting observed in metallic plasmonic structures. The amplification of high harmonics is observed by coupling only 5-10 nano-joules of a 3.2 µm high repetition-rate OPCPA laser at the entrance of each nanocone. Harmonic amplification (factor 30) depends on the laser energy input, wavelength and nanocone geometry [2]. [1] Vampa et al., Nat. Phys. 13, 659–662 (2017). [2] Franz et al., arXiv:1709.09153 [physics.optics] (2017)

Published
2018

26. High harmonic generation in graphene (Conference Presentation)

Author

Rana Nicolas, Dominik Franz, Shatha Kaassamani, David Gauthier, Willem Boutu, and Hamed Merdji

Subjects
Materials science, Graphene, Band gap, business.industry, Substrate (electronics), law.invention, law, Harmonics, Monolayer, Femtosecond, Harmonic, High harmonic generation, Optoelectronics, business
Abstract

Graphene is a remarkable material, a monolayer of carbon atoms bonded together in a honeycomb structure that exhibits extraordinary electronic and optoelectronic properties; such as a zero band gap energy, high electron mobility and ultrahigh mechanical strength. The electronic properties of graphene can lead to nonlinear optical processes such as high harmonic generation. Here, we investigate high harmonic generation in several graphene configurations. We first report on the observation of harmonic generation in monolayer graphene on a quartz substrate. We measured up to the ninth harmonic (233 nm wavelength) from graphene of a mid-infrared femtosecond laser, whose wavelength is 2.1 µm, pulse energy around 6 nJ, pulse duration 85 fs, and repetition rate 18 MHz. Our findings confirm recent observations [1]. We then report for the first time on the observation of harmonics from free-standing graphene supported on TEM grids. Free-standing graphene, in contrast to graphene on a substrate behaves differently; mainly due to the lack of its interaction with the substrate which alters its band gap. We will present major trends of high harmonic generation dependence with laser polarization, intensity and a study on damages issues [2]. [1] Yoshikawa et al., Science 356, 736_738 (2017) [2] Nicolas et al. submitted.

Published
2018

27. Resonant-Plasmon-Assisted Subwavelength Ablation by a Femtosecond Oscillator

Author

Tamas Nagy, Bianca Iwan, Willem Boutu, Uwe Morgner, T. Heidenblut, Milutin Kovacev, Carsten Reinhardt, Quentin Ripault, Ihar Babuskin, Seung-Woo Kim, Seunghwoi Han, Jose R. C. Andrade, Bert Bastiaens, G. Steinmeyer, Rana Nicolas, Hyunwoong Kim, Dominik Franz, Hamed Merdji, Liping Shi, Institut für Quantenoptik [Hannover] (IQ), Leibniz Universität Hannover=Leibniz University Hannover, Centre for Quantum Engineering and Space-time Research (QUEST), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Electrical Engineering [Korea Advanced Institute of Science and Technology] (KAIST), Korea Advanced Institute of Science and Technology (KAIST), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut für Werkstoffkunde, Leibniz Universität Hannover, Laser Zentrum Hannover, Institute for Nanotechnology (MESA+), University of Twente, Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI), ANR-16-CE30-0027,HELLIX,Source laser à taux de répétition élevé pour l'imagerie par diffraction cohérente XUV(2016), Leibniz Universität Hannover [Hannover] (LUH), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), University of Twente [Netherlands], and Laser Physics & Nonlinear Optics

Subjects
Materials science, Nanophotonics, General Physics and Astronomy, Physics::Optics, 02 engineering and technology, Dielectric, subwavelength optical nanoantenna, 7. Clean energy, 01 natural sciences, sapphire oscillator [Ti], 0103 physical sciences, High harmonic generation, ddc:530, 010306 general physics, Plasmon, [PHYS]Physics [physics], Laser ablation, business.industry, Surface plasmon, 021001 nanoscience & nanotechnology, Field electron emission, Femtosecond, Optoelectronics, nanoscale ablation, 0210 nano-technology, business
Abstract

We experimentally demonstrate the use of subwavelength optical nanoantennas to assist a direct nanoscale ablation using the ultralow fluence of a Ti:sapphire oscillator through the excitation of surface plasmon waves. The mechanism is attributed to nonthermal transient unbonding and electrostatic ablation, which is triggered by the surface plasmon-enhanced field electron emission and acceleration in vacuum. We show that the electron-driven ablation appears for both nanoscale metallic as well as dielectric materials. While the observed surface plasmon-enhanced local ablation may limit the applications of nanostructured surfaces in extreme nonlinear nanophotonics, it, nevertheless, also provides a method for nanomachining, manipulation, and modification of nanoscale materials. Collateral thermal damage to the antenna structure can be suitably avoided, and nonlinear conversion processes can be stabilized by a dielectric overcoating of the antenna. © 2018 American Physical Society.

Published
2018

28. Orbital angular momentum from semiconductor high-order harmonics

Author

David Gauthier, Willem Boutu, Sébastien Février, Dominik Franz, Rana Nicolas, Dmitry Gaponov, Shatha Kaassamani, Marc Hanna, Jean-Thomas Gomes, Laure Lavoute, Gaëtan Jargot, Hamed Merdji, Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Fabry / Lasers, Laboratoire Charles Fabry (LCF), Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)-Institut d'Optique Graduate School (IOGS)-Centre National de la Recherche Scientifique (CNRS), Novae, Photonique Fibre et Sources Cohérentes (XLIM-PHOT), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Ultrafast scientific Instrumentation (FASTLITE), École polytechnique (X), ANR-16-CE08-0031,BISCOT,Sources à supercontinuum large bande dans le moyen infra-rouge(2016), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS)-Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS)

Subjects
Angular momentum, Physics::Optics, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, 7. Clean energy, law.invention, 010309 optics, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], Optics, law, 0103 physical sciences, Light beam, Quantum information, Physics, business.industry, 021001 nanoscience & nanotechnology, Laser, Atomic and Molecular Physics, and Optics, Semiconductor, Optical tweezers, Harmonics, 0210 nano-technology, business, Optical vortex, Physics - Optics, Optics (physics.optics)
Abstract

Light beams carrying orbital angular momentum (OAM) have led to stunning applications in various fields from quantum information to microscopy. In this letter, we examine OAM from the recently discovered high-harmonic generation (HHG) in semiconductor crystals. HHG from solids could be a valuable approach for integrated high-flux short-wavelength coherent light sources. The solid state nature of the generation medium allows the possibility to tailor directly the radiation at the source of the emission and offers a substantial degree of freedom for spatial beam shaping. First, we verify the fundamental principle of the transfer and conservation of the OAM from the generation laser to the harmonics. Second, we create OAM beams by etching a spiral zone structure directly at the surface of a zinc oxide crystal. Such diffractive optics act on the generated harmonics and produces focused optical vortices with nanometer scale sizes that may have potential applications in nanoscale optical trapping and quantum manipulation.

Published
2018
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29. Ultrafast fiber lasers at 2 μm and applications

Author

Laure Lavoute, Nicolas Ducros, Jean-Thomas Gomes, Hamed Merdji, Mathieu Jossent, Kirill I. Zaytsev, Dmitry Gaponov, Ammar Hideur, Ferenc Borondics, Sébastien Février, Novae, Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Photonique Fibre et Sources Cohérentes (XLIM-PHOT), XLIM (XLIM), Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE08-0031,BISCOT,Sources à supercontinuum large bande dans le moyen infra-rouge(2016)

Subjects
[PHYS]Physics [physics], [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Materials science, business.industry, 02 engineering and technology, 021001 nanoscience & nanotechnology, 7. Clean energy, 01 natural sciences, 010309 optics, Fiber laser, 0103 physical sciences, Optoelectronics, 0210 nano-technology, business, Ultrashort pulse
Abstract

International audience; This paper reviews our recent results on the development of ultrafast (100 ps – 100 fs) fiber lasers at 2 μm wavelength and their applications from mid-infrared spectroscopy to UV generation in graphene and micromachining of polymers.

Published
2018

30. High Harmonic Generation in 2D and 3D semiconductors

Author

Hamed Merdji

Subjects
Coupling, Materials science, Condensed Matter::Other, Graphene, business.industry, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, law.invention, Condensed Matter::Materials Science, Semiconductor, law, Harmonics, Local field enhancement, Optoelectronics, High harmonic generation, business, Laser beams
Abstract

We show the amplification of non-perturbative harmonics by local field enhancement in 3D semiconductors. Then, we investigate high harmonic generation in free standing 2D graphene. Finally, we propose routes for spatio-temporal coupling using 3D nanostructured semiconductors.

Published
2018

31. Ultrafast nanoscale imaging using high order harmonic generation (Conference Presentation)

Author

Hamed Merdji

Subjects
Physics, Photon, business.industry, Attosecond, Holography, Laser, 01 natural sciences, law.invention, 010309 optics, Optics, law, 0103 physical sciences, Femtosecond, High harmonic generation, Imaging science, 010306 general physics, business, Ultrashort pulse
Abstract

Ultrafast coherent diffraction using soft and hard X-rays is actually revolutionizing imaging science thanks to new sources recently available. This powerful technique extends standard X-ray diffraction towards imaging of non-crystalline objects and leads actually to a strong impact in physics, chemistry and biology. New ultrashort pulses recently available hold the promise of watching matter evolving with unprecedented space and time resolution. Femtosecond coherent and intense radiation in the soft X-ray (λ = 10-40 nm) is currently produced in our laboratory, from highly non linear frequency conversion (high harmonic generation). A high intensity UV-X coherent beam is obtained using a loose focusing geometry, which allows coupling a very high amount of Ti:Sapphire laser system energy in the HHG process. Using a long gas cell and a long focal length lens, the emitting volume can be increased by orders of magnitude compared to standard HHG set-ups. This approach, allows reaching up to 1x1011 photons per shot for the 25th harmonic (λ=32nm). We have already demonstrated nanoscale imaging in a single shot mode reaching 70 nm spatial resolution and 20 femtoseconds snapshot [1]. We then implemented a recently proposed holographic technique using extended references. This technique, easy to implement, allows a direct non iterative image reconstruction. In the single shot regime, we demonstrated a spatial resolution of 110nm [2].This opens fascinating perspectives in imaging dynamical phenomena to be spread over a large scientific community. I will present recent results in the investigation of femtosecond phase spin-reversals of magnetic nano-domains [3]. Finally, I will report on recent development on noise sensitivity of the technique and perspectives in attosecond coherent imaging [4]. [1] A. Ravasio et al., Physical Review Letters 103, 028104 (2009). [2] D. Gauthier et al., Physical Review Letters 105, 093901 (2010). [3] Vodungbo et al., Nature Communications 3, 999 (2012) [4] Williams et al., Optics Letters 40 (13), 3205 (2015)

Published
2017

32. Single-shot spatial coherence characterization of x-ray ultrafast sources

Author

Duarte, Joana, Gonzalez, Aura Inés, Cassin, Rémy, Nicolas, Rana, Kholodstova, Maria, Boutu, Willem, Fajardo, Marta, and Hamed, Merdji

Abstract

Spatial coherence is an impactful source parameter in many applications ranging from atomic and molecular physics to metrology or imaging. In lensless imaging, for example, it can strongly affect the image formation, especially when the source exhibits shot-to-shot variations. Single-shot characterization of the spatial coherence length of a source is thus crucial. However, current techniques require either parallel intensity measurements or the use of several masks. Based on the method proposed by González et al. [J. Opt. Soc. Am. A28, 1107 (2011)JOAOD60740-323210.1364/JOSAA.28.001107], we designed a specific arrangement of a two-dimensional non-redundant array of apertures, which allows, through its far field interference pattern, for a single-shot measurement of the spatial coherence, while being robust against beam-pointing instabilities. The strategic configuration of the pinholes allows us to disentangle the degree of spatial coherence from the intensity distribution, thus removing the need for parallel measurement of the beam intensity. An experimental validation is performed using a high-harmonic source. A statistical study in different regimes shows the robustness of the method.

Published
2021

33. Impact of noise in holography with extended references in the low signal regime

Author

R. Cassin, Fenglin Wang, M. Ducousso, Milutin Kovacev, Hamed Merdji, J. Samaan, X. Ge, Bianca Iwan, Willem Boutu, A. I. Gonzalez, D. Gauthier, Attophysique (ATTO), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Leibniz Universität Hannover [Hannover] (LUH), and Leibniz Universität Hannover=Leibniz University Hannover

Subjects
Diffraction, Physics, [PHYS]Physics [physics], business.industry, Holography, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, Image processing, Iterative reconstruction, 01 natural sciences, Signal, Noise (electronics), Atomic and Molecular Physics, and Optics, law.invention, 010309 optics, Optics, Software, law, 0103 physical sciences, Harmonic, 010306 general physics, business
Abstract

International audience; Signal-to-noise ratio is a key factor in lensless imaging, particularly for low diffraction signal experiments in the single shot regime.We present our recent study of the noise impact on holography with extended references. Experimental data have been measured in single shot acquisition using an intense coherent soft X-ray high harmonic source. The impact of hardware and software noise under various detection conditions is discussed. A final comparison between single shot and multi-shot regimes is given.

Published
2016

34. Imagerie nanométrique femtoseconde par diffraction X cohérente

Author

Hamed Merdji and Willem Boutu

Abstract

Dans de nombreux domaines de la science, nous cherchons a voir la matiere evoluer en temps reel. Imager des objets individuels en combinant des resolutions spatiales de l’ordre du nanometre (10-9 m) et temporelles de l’ordre de la femtoseconde (1 fs = 10-15 s) represente donc un enjeu important. Tres recemment, le developpement des sources X coherentes recentes de type « laser » nous permet d’atteindre des resolutions jusque-la inegalees. C’est dans ce contexte que se situent les recherches menees par le laboratoire Attophysique du CEA Saclay : developper de nouvelles sources de lumiere ultra-breves, controlees, dans le domaine des rayons X, afin d’imager des phenomenes physiques, chimique, biologiques, a une echelle spatiale atomique/nanometrique avec des resolutions temporelles attoseconde/femtoseconde.

Published
2012

35. Surface modification of polymethylmethacrylate irradiated with 60fs single laser pulses

Author

Libor Juha, Dorota Klinger, D. Żymierska, Hamed Merdji, Stéphane Guizard, Marek Jurek, Jerzy B. Pelka, Ryszard Sobierajski, Robert Nietubyć, and Jacek Krzywinski

Subjects
Radiation, Materials science, business.industry, Pulse (signal processing), medicine.medical_treatment, Ablation, Laser, law.invention, X-ray laser, Optics, Impact crater, law, Femtosecond, medicine, Surface modification, Irradiation, business
Abstract

An ablation by a femtosecond laser pulses of polymethylmethacrylate was investigated in the near-infrared region. The morphological changes due to increasing laser fluency were examined. The size and shape as well as morphological forms occurring in the resulted craters were analyzed as a function of irradiation fluency. Various forms of surface modifications in ablated crater i.e. cracks and smaller features like honey-comb-like structures, and ripples with an average period of 800 nm were observed. The threshold fluency for observable changes of the sample surface, the ablation threshold and the threshold fluency for creation of the structure in the centre of the cavity were determined for 60 fs laser pulse. Obtained data were compared with available literature data.

Published
2009

36. Injection of harmonics generated in gas in a free-electron laser providing intense and coherent extreme-ultraviolet light

Author

T. Tanikawa, Marie Labat, Bertrand Carré, D. Garzella, Hideo Kitamura, Tsumoru Shintake, M. Bougeard, Guillaume Lambert, Pascal Salières, M. E. Couprie, S. Inoue, Olivier Gobert, Yoshihito Tanaka, K. Tahara, Hamed Merdji, Oleg Chubar, and Toru Hara

Subjects
Physics, Water window, Orders of magnitude (temperature), business.industry, Free-electron laser, General Physics and Astronomy, Laser, law.invention, Wavelength, Optics, law, Extreme ultraviolet, Harmonics, Photonics, business
Abstract

Seeding a free-electron laser with pulses from a high-harmonic UV-light source increases its output intensity by three orders of magnitude. This approach has the potential to generate temporally coherent light at wavelengths down to the all-important ‘water window’, vital for studying biological samples.

Published
2008

37. Time resolved luminescence of solids excited by femtosecond VUV pulses and synchrotron radiation

Author

Hamed Merdji, P. Martin, Sebastian Vielhauer, Stéphane Guizard, Andrei Belsky, Eduard Feldbach, Nikita Fedorov, M. De Grazia, Bertrand Carré, Vitali Nagirnyi, V. Babin, and Marco Kirm

Subjects
Chemistry, Physics::Optics, Synchrotron radiation, Condensed Matter Physics, Laser, law.invention, law, Excited state, Femtosecond, High harmonic generation, ddc:530, Emission spectrum, Atomic physics, Spectroscopy, Luminescence
Abstract

Time-resolved luminescence spectroscopy has been widely used in studies of electronic excitations and their dynamics in insulators. Present paper discusses the potential of vacuum ultraviolet spectroscopy applied for wide band gap crystals using classical synchrotron radiation as well as more recently developed pulsed femtosecond short-wavelength light sources. Optical spectroscopy using novel free electron lasers and laser systems based on higher harmonic generation process allow detailed investigation of the interaction between electronic excitations and behaviour of solids under extreme radiation conditions. Significant changes in the quantum yield and emission decay kinetics as well as surface damage of single crystals were observed for CdWO4 and CaWO4 crystals studied in the temperature range of 8-300 K. However, in the range of excitation densities applied, up to ∼1012 W/cm2, the nature of luminescence centres and their characteristic emission spectra remained similar to those observed at low excitation densities. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Published
2007

38. Shot-to-shot intensity and wavefront stability of high-harmonic generation

Author

S. Künzel, Marta Fajardo, Guillaume Dovillaire, Philippe Zeitoun, Hamed Merdji, Bob Nagler, Ulf Zastrau, Willem Boutu, B. Barbrel, Hae Ja Lee, Eric Galtier, Gareth O. Williams, Richard W. Lee, Instituto de Telecomunicações [Lisboa, Portugal], Service des Photons, Atomes et Molécules (SPAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), SLAC National Accelerator Laboratory (SLAC), Stanford University, Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Friedrich-Schiller-Universität = Friedrich Schiller University Jena [Jena, Germany], Imagine Optic, AFOP, Department of Psychics, Laboratoire d'optique appliquée (LOA), and École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Wavefront, Physics, Spectrometer, [PHYS.PHYS]Physics [physics]/Physics [physics], business.industry, Phase (waves), Wavefront sensor, Atomic and Molecular Physics, and Optics, Intensity (physics), Optics, Temporal resolution, High harmonic generation, Plasma diagnostics, Electrical and Electronic Engineering, business, Engineering (miscellaneous)
Abstract

International audience; We report on the shot-to-shot stability of intensity and spatial phase of high-harmonic generation (HHG). The intensity stability is measured for each high-harmonic (HH) order with a spectrometer. Additionally, the spatial phase is measured with an XUV wavefront sensor for a single HH order measured in a single shot, which according to our knowledge was not reported before with a Hartmann wavefront sensor. Furthermore, we compare the single-shot measurement of the spatial phase with time-integrated measurements and we show that the XUV wavefront sensor is a useful tool to simultaneously optimize the spatial phase and intensity of HHG within the available HHG parameter range used in this study.

Published
2015

39. Spectral-phase interferometry for direct electric-field reconstruction applied to seeded extreme-ultraviolet free-electron lasers

Author

David Garzella, Jean-Philippe Rousseau, Hamed Merdji, Benoît Mahieu, Hugo Dacasa, David Gauthier, Magali Lozano, Philippe Zeitoun, Giovanni De Ninno, Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Elettra Sincrotrone Trieste, Serveurs Laser (SLIC), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Attophysique (ATTO)

Subjects
[PHYS]Physics [physics], Materials science, business.industry, Phase (waves), FOS: Physical sciences, Laser, Spectral phase interferometry for direct electric-field reconstruction, 01 natural sciences, Atomic and Molecular Physics, and Optics, law.invention, 010309 optics, Interferometry, Optics, law, Extreme ultraviolet, Electric field, 0103 physical sciences, Femtosecond, High harmonic generation, Physics::Accelerator Physics, 010306 general physics, business, Physics - Optics, Optics (physics.optics)
Abstract

International audience; We present a setup for complete characterization of femtosecond pulses generated by seeded free-electron lasers (FELs) in the extreme-ultraviolet spectral region. Two delayed and spectrally shifted replicas are produced and used for spectral phase interferometry for direct electric field reconstruction (SPIDER). We show that it can be achieved by a simple arrangement of the seed laser. Temporal shape and phase obtained in FEL simulations are well retrieved by SPIDER reconstructions, allowing to foresee the implementation of this diagnostics tool on existing and future sources. This will be a significant step towards an experimental investigation and control of FEL spectral phase.

Published
2015

40. Fourier transform holography with high harmonic spectra for attosecond imaging applications

Author

S. Künzel, Eduardo Oliva, Bianca Iwan, Willem Boutu, A. I. Gonzalez, Hamed Merdji, Marta Fajardo, Ph. Zeitoun, Gareth O. Williams, S. Daboussi, M. Lozano, Lianhe Li, Instituto de Telecomunicações [Lisboa, Portugal], Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de physique des gaz et des plasmas (LPGP), and Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, [PHYS]Physics [physics], business.industry, Attosecond, Holography, Physics::Optics, Atomic and Molecular Physics, and Optics, law.invention, symbols.namesake, Imaging spectroscopy, Fourier transform, Optics, law, Harmonics, Discrete frequency domain, symbols, Harmonic, Physics::Atomic Physics, business, Image resolution
Abstract

International audience; We demonstrate a method of using a Fourier holographic technique to utilize attosecond soft x-ray pulses to image nanometer-scale objects. A discrete frequency comb of laser-generated high-order harmonics, yielding a train of attosecond pulses, has been used to record spatially and spectrally resolved images. The individual wavelengths were also combined to form a single image, albeit with lower spatial resolution, demonstrating the applicability of the method to using isolated attosecond pulses with continuous bandwidths.

Published
2015

41. Overview on HHG High-Flux Sources

Author

Jean-François Hergott, Hamed Merdji, Willem Boutu, and M. Ducousso

Subjects
Physics, Photon, business.industry, Energy conversion efficiency, Physics::Optics, Nonlinear optics, Laser, law.invention, Optics, Orders of magnitude (time), law, Extreme ultraviolet, High harmonic generation, business, Order of magnitude
Abstract

High order laser harmonic generation is a relatively recent and promising source of intense coherent radiation in the extreme ultraviolet and soft X-ray domains. The process, due to the highly non linear interaction between an intense and ultrashort laser pulse and a gas medium, has a relatively low efficiency at the single atom level. However, progresses in laser technology and a better understanding of the macroscopic construction of the harmonic field have enabled high flux sources. In this chapter, we will review the last developments that allow the publication of the first demonstrations of photon demanding experiments in solid state physics and non linear optics. Control and shaping of the fundamental laser field have led to an increase of the conversion efficiency of several orders of magnitude. Microjoule level emissions have been obtained on high power lasers thanks to phase matching and quasi phase matching schemes. We will also mention very high repetition rate laser systems that produce photon flux per second of the same order of magnitude than those obtained with lower repetition rate and higher energy level.

Published
2015

42. Spatial quality improvement of a Ti:Sapphire laser beam by modal filtering

Author

Hamed Merdji, M. Perdrix, X. Ge, Willem Boutu, Fan Wang, Olivier Gobert, David Garzella, David Gauthier, Benoît Mahieu, Fabien Lepetit, Thierry Auguste, Bertrand Carré, Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Elettra Sincrotrone Trieste, Serveurs Laser (SLIC), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Attophysique (ATTO), Laboratoire Pierre Aigrain (LPA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Materials science, Physics and Astronomy (miscellaneous), Spatial filter, business.industry, General Engineering, Ti:sapphire laser, General Physics and Astronomy, Physics::Optics, 01 natural sciences, Beam parameter product, 010309 optics, Optics, 0103 physical sciences, High harmonic generation, Physics::Accelerator Physics, M squared, Laser beam quality, 010306 general physics, business, Beam (structure), Gaussian beam
Abstract

International audience; We present a study on the improvement of the spatial quality of a laser beam, called modal filtering,suitable to high-energy lasers. The method is theoretically compared with the classical pinhole filtering technique in the case of an astigmatic Gaussian beam, illustrating, in this particular case, its efficiency for filtering low spatial frequencies. Experimental study of the modal filtering of a temporally chirped beam from a Ti:Sapphire chirped-pulseamplification system is presented. Beam profile, wavefront and pulse duration after compression were measured, showing a dramatic improvement of beam quality and no modifications of the temporal distribution. High-order harmonic generation in a rare gas, a highly nonlinear process which is phase-matching dependent, was used to test the effect of the filter and showed a clear enhancement of the generation.

Published
2015

43. Interaction d'impulsions VUV intenses avec les solides luminescents

Author

Peter G. Martin, Stéphane Guizard, G. Geoffroy, Eduard Feldbach, Bertrand Carré, Vitali Nagirnyi, M. De Grazia, Nikita Fedorov, Guillaume Petite, Jérôme Gaudin, Andrei Belsky, Hamed Merdji, and Marco Kirm

Subjects
Physics, Analytical chemistry, General Physics and Astronomy, Time resolution, High field
Abstract

Nous presentons les resultats d'etudes de luminescence resolue en temps emise par des cristaux sous excitation par des photons VUV issus de la generation d'harmoniques d'ordre eleve. L'utilisation d'un laser Ti-Sa PLFA a Saclay, qui delivre des impulsions d'une energie de 13 mJ et d'une duree de 35 fs a 1 KHz, pour la generation des harmoniques dans l'Argon et la microfocalisation du faisceau VUV nous ont permis de faire varier la densite du rayonnement sur la cible dans une large gamme. Nous avons etudie l'effet de la densite d'excitation VUV sur la luminescence intrinseque de cristaux a large bande interdite (CdWO 4 et BaF 2 ). En fonction de la densite d'excitation VUV nous avons observe les modifications des spectres d'emission et de la cinetique de la luminescence excitonique. Quand la densite d'excitation VUV croit, le rendement de la luminescence diminue et apparaissent dans la cinetique de luminescence des composantes rapides. Le profil de la courbe de declin devient alors complexe avec une forte deviation de la loi exponentielle dans sa partie initiale.

Published
2006

44. Utilisation des matériaux luminescents pour la métrologie des faisceaux intenses UVX d'impulsions ultracourtes

Author

Jérôme Gaudin, Vitali Nagirnyi, Nikita Fedorov, Andrei Belsky, M. De Grazia, Bertrand Carré, Hamed Merdji, G. Geoffroy, Andrey N. Vasil’ev, Peter G. Martin, Marco Kirm, Stéphane Guizard, and Eduard Feldbach

Subjects
General Physics and Astronomy
Abstract

Recemment nous avons debute des series d'experiences sur l'interaction d'impulsions intenses VUV avec les solides luminescents. Le but principal en est l'etude des mecanismes d'interaction et de transfert d'energie entre les excitations electrcniques dans les solides a large bande interdite. L'application directe de ces etudes sera le developpement de materiaux et de methodes de metrologie pour les faisceaux UVX intenses. Nous presentons les resultats obtenus pour CdWO 4 qui montrent que ce cristal pourra servir comme un scintillateur pour le rayonnement VUV intense.

Published
2006

45. Generation of attosecond pulses in molecular nitrogen

Author

Willem Boutu, Katalin Varjú, P. Monchicourt, P. Breger, Leszek J. Frasinski, M. Vitteau, M. Stankiewicz, Per Johnsson, Pascal Salières, Yann Mairesse, Bertrand Carré, Hamed Merdji, and H. Wabnitz

Subjects
Physics, Argon, Attosecond, Optical physics, chemistry.chemical_element, Nonlinear optics, Diatomic molecule, Atomic and Molecular Physics, and Optics, Amplitude, chemistry, Pulse wave, ddc:530, Atomic physics, Ultrashort pulse
Abstract

We have generated attosecond pulse trains in an ensemble of randomly aligned nitrogen molecules. Measurements of the high-order harmonic relative phases and amplitudes allow us to reconstruct the temporal profile of the attosecond pulses. We show that in the considered spectral range, the latter is very similar to the pulse train generated in argon under the same conditions. We discuss the possible influence of the molecular structure in the generation process, and how it can induce subtle differences on the relative phases.

Published
2006

46. A high-intensity highly coherent soft X-ray femtosecond laser seeded by a high harmonic beam

Author

D. Aubert, Gabriel Faivre, Philippe Balcou, Stéphane Sebban, Marta Fajardo, Tomas Mocek, G. de Lacheze-Murel, Sophie Kazamias, Frédéric Burgy, Hamed Merdji, A. Hallou, T. Lefrou, S. Le Pape, Denis Douillet, Anne-Sophie Morlens, Philippe Zeitoun, Jean-Philippe Rousseau, Constance Valentin, Pascal Mercère, Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centro de Física dos Plasmas, Instituto Superior Técnico, Universidade Técnica de Lisboa (IST), DAM Île-de-France (DAM/DIF), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire d'interaction du rayonnement X avec la matière (LIXAM), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Laboratoire pour l'utilisation des lasers intenses (LULI), Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Service des Photons, Atomes et Molécules (SPAM), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Soft x ray, Multidisciplinary, Materials science, business.industry, Amplifier, Nonlinear optics, Plasma, Laser, 01 natural sciences, Optical quality, law.invention, 010309 optics, Optics, law, 0103 physical sciences, Femtosecond, Optoelectronics, 010306 general physics, business, Coherence (physics)
Abstract

International audience; Synchrotrons have for decades provided invaluable sources of soft X-rays, the application of which has led to significant progress in many areas of science and technology. But future applications of soft X-rays—in structural biology, for example—anticipate the need for pulses with much shorter duration (femtoseconds) and much higher energy (millijoules) than those delivered by synchrotrons. Soft X-ray free-electron lasers1 should fulfil these requirements but will be limited in number; the pressure on beamtime is therefore likely to be considerable. Laser-driven soft X-ray sources offer a comparatively inexpensive and widely available alternative, but have encountered practical bottlenecks in the quest for high intensities. Here we establish and characterize a soft X-ray laser chain that shows how these bottlenecks can in principle be overcome. By combining the high optical quality available from high-harmonic laser sources (as a seed beam) with a highly energetic soft X-ray laser plasma amplifier, we produce a tabletop soft X-ray femtosecond laser operating at 10 Hz and exhibiting full saturation, high energy, high coherence and full polarization. This technique should be readily applicable on all existing laser-driven soft X-ray facilities.

Published
2004

47. Status of the SPARC project

Author

S. Pagnutti, P. Emma, M. Preger, D. Alesini, C. De Martinis, Rodolfo Bonifacio, P.L. Ottaviani, James Rosenzweig, Luigi Palumbo, M. Quattromini, F. Tazzioli, R. Boni, Alessandro Cianchi, Adolfo Esposito, Simone Cialdi, Gian Piero Gallerano, V. Fusco, Pascal Salières, F. Sgamma, Massimo Ferrario, O. Tcherbakoff, L. Cultrera, R. Ricci, Andrea Doria, Ilario Boscolo, M. G. Castellano, Alessio Perrone, Dario Giove, Carlo Ligi, Luca Ficcadenti, G. Parisi, Alberto Clozza, Sven Reiche, P. Monchicourt, Pierre Breger, Angelo Stella, C. Schaerf, Daniele Pelliccia, Luca Giannessi, M. Sassi, A. Dipace, Vittoria Petrillo, M.E. Couprie, M. Bougeard, Marie Labat, G. Ronci, Andrea Mostacci, Alberto Renieri, A. Ghigo, Luigi Pellegrino, Guillaume Lambert, F. Ciocci, G. Di Pirro, Daniele Filippetto, Giuseppe Dattoli, L. Catani, Concetta Ronsivalle, Emilio Giovenale, C. Maroli, Enrica Chiadroni, Bruno Spataro, Hamed Merdji, Alessandro Flacco, Carlo Vicario, Luigi Picardi, G. Gatti, Amalia Torre, Francesco Flora, Mario Serio, Manuela Boscolo, Cristina Vaccarezza, Bertrand Carré, D. Garzella, E. Gabrielli, Alberto Bacci, Andrea Rossi, P. Musumeci, Elio Sabia, F. Broggi, Massimo Petrarca, A. Drago, Marco Bellaveglia, G. Messina, C. Sanelli, M. Rosetti, Fabrizio Castelli, E. Pace, F. Alessandria, Claudio Pellegrini, Alessandro Gallo, Luca Serafini, A. Zucchini, Mario Mattioli, S. Bertolucci, M. Vescovi, Mauro Migliorati, Agostino Marinelli, D., Alesini, S., Bertolucci, M. E., Biagini, C., Biscari, R., Boni, M., Boscolo, M., Castellano, A., Clozza, G., DI PIRRO, A., Drago, A., Esposito, M., Ferrario, V., Fusco, A., Gallo, A., Ghigo, S., Guiducci, M., Incurvati, C., Ligi, F., Marcellini, M., Migliorati, C., Milardi, A., Mostacci, L., Palumbo, L., Pellegrino, M., Preger, P., Raimondi, R., Ricci, C., Sanelli, M., Serio, F., Sgamma, B., Spataro, A., Stecchi, A., Stella, F., Tazzioli, C., Vaccarezza, M., Vescovi, C., Vicario, M., Zobov, F., Alessandria, A., Bacci, I., Boscolo, F., Broggi, S., Cialdi, C., Demartini, D., Giove, C., Maroli, M., Mauri, V., Petrillo, M., Rom, L., Serafini, Levi, Decio, M., Mattioli, G., Medici, L., Catani, E., Chiadroni, S., Tazzari, R., Bartolini, F., Ciocci, G., Dattoli, A., Doria, F., Flora, G. P., Gallerano, L., Giannessi, E., Giovenale, G., Messina, L., Mezi, P. L., Ottaviani, S., Pagnutti, L., Picardi, M., Quattromini, A., Renieri, C., Ronsivalle, A., Cianchi, A. D., Angelo, R., DI SALVO, A., Fantini, D., Moricciani, C., Schaerf, and J. B., Rosenzweig

Subjects
Physics, Nuclear and High Energy Physics, Brightness, SASE-FEL, high brightness electron beam, business.industry, Particle accelerator, Modular design, Undulator, Linear particle accelerator, Settore FIS/04 - Fisica Nucleare e Subnucleare, law.invention, non-linear resonant higher harmonics, Optics, photo-injector, law, Spark (mathematics), Radio frequency, Beam emittance, Aerospace engineering, business, Instrumentation
Abstract

SPARC-X is a two branch project consisting in the SPARC test facility dedicated to the development and test of critical subsystems such as high brightness photoinjector and a modular expandable undulator for SASE-FEL experiments at 500 nm with seeding, and the SPARK facility aiming at generation of high brilliance coherent radiation in the 1.5-13 nm range, based on the achieved expertise. The projects are supported by MIUR (Research Department of Italian Government) and Regione Lazio. SPARC has completed the commissioning phase of the photoinjector in November 2006. The achieved experimental results are here summarized together with the status of the second phase commissioning plans. The SPARK project is based on the generation of ultra high peak brightness electron beams at the energy of 1 and 2 GeV generating radiation in the 1.5-13 nm range. The construction is at the moment planned in two steps starting with a 1 GeV Linac. The project layout including both RF-compression and magnetic chicane techniques has been studied.

Published
2004

48. Manipulating intense XUV coherent light in the temporal domain

Author

Hamed Merdji, J.-F. Hergott, E. Priori, Milutin Kovacev, Bertrand Carré, and Pascal Salières

Subjects
Physics, Optics, business.industry, Attosecond, Extreme ultraviolet, Optoelectronics, Electrical and Electronic Engineering, Condensed Matter Physics, business, Atomic and Molecular Physics, and Optics, Phase locking, Domain (software engineering)
Abstract

In this article, we demonstrate the generation of four phase-locked harmonic pulses separated in time using frequency-domain interferometry. The spectra present a high sensitivity to a change of the relative phase on an attosecond time scale. The spectral resolution and the control of this relative phase could be used to perform high resolution measurements.

Published
2004

49. Attosecond Synchronization of High-Harmonic Soft X-rays

Author

Pierre Agostini, L. C. Dinu, P. Monchicourt, Leszek J. Frasinski, Milutin Kovacev, A de Bohan, Bertrand Carré, Richard Taïeb, Pierre Breger, Yann Mairesse, Pascal Salières, H. G. Muller, and Hamed Merdji

Subjects
Physics, Multidisciplinary, business.industry, Attosecond, Pulse duration, Attophysics, Laser, law.invention, Pulse (physics), Optics, law, Harmonics, Harmonic, business, Ultrashort pulse
Abstract

Subfemtosecond light pulses can be obtained by superposing several high harmonics of an intense laser pulse. Provided that the harmonics are emitted simultaneously, increasing their number should result in shorter pulses. However, we found that the high harmonics were not synchronized on an attosecond time scale, thus setting a lower limit to the achievable x-ray pulse duration. We showed that the synchronization could be improved considerably by controlling the underlying ultrafast electron dynamics, to provide pulses of 130 attoseconds in duration. We discuss the possibility of achieving even shorter pulses, which would allow us to track fast electron processes in matter.

Published
2003

50. Temporal confinement of the harmonic emission through polarization gating

Author

O. Tcherbakoff, Eric Mével, Eric Constant, Yann Mairesse, E. Priori, P. Monchicourt, Milutin Kovacev, Hamed Merdji, Pierre Agostini, Pierre Breger, Bertrand Carré, and Pascal Salières

Subjects
Physics, Frequency-resolved optical gating, business.industry, Optical physics, Physics::Optics, Optical polarization, Plasma, Polarization (waves), Laser, Atomic and Molecular Physics, and Optics, law.invention, Optics, law, Harmonics, High harmonic generation, business
Abstract

We show experimentally that a simple optical setup is able to reduce the duration of the harmonic emission generated by “long” (many optical cycles) laser pulses. By controlling the time-dependent ellipticity during the laser pulse, one can confine the harmonic emission to a narrow temporal window where the polarization is quasi-linear. The results obtained and their comparison with a simple model show a shortening of a factor 2 for harmonics located in the plateau region. Using shorter laser pulses of 15-20 fs duration should make it possible to isolate a single attosecond pulse.

Published
2003

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