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158 results on '"Armelles, Gaspar"'

1. Giant Magneto-refractive Effect in Second Harmonic Generation from Plasmonic Antennas in the Mid-infrared

Author

Razdolski, Ilya, Armelles, Gaspar, Cebollada, Alfonso, and Kirilyuk, Andrey

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Other Condensed Matter, Physics - Optics
Abstract

Metallic nanostructures exhibit strong nonlinear-optical response at surface plasmon resonances, where the light-matter coupling efficiency is enhanced. An active modulation of this response can be realized by means of an external magnetic field. Here we utilize a nonlinear magneto-refractive effect in spintronic multilayer antennas to achieve a resonant 20\% modulation in second harmonic generation (SHG) in the mid-infrared. We discuss mechanisms of this modulation and show that it cannot be explained by an unequal enhancement of the electromagnetic field in the two spin states of the multilayer. Instead, we propose a novel contribution to the nonlinear susceptibility, which relies on the spin-dependent electron mean free path in metals. In contrast to magneto-optics in ferromagnets, our approach results in no shift of the resonance and thus ensures that the largest SHG and its strongest modulation are simultaneously observed., Comment: 5 pages, 4 figures

Published
2020

2. Switching the Optical Chirality in Magneto-plasmonic Metasurfaces Using Applied Magnetic Fields

Author

Qin, Jun, Deng, Longjiang, Kang, Tongtong, Nie, Lixia, Feng, Huayu, Wang, Huili, Yang, Run, Liang, Xiao, Tang, Tingting, Li, Chaoyang, Wang, Hanbin, Luo, Yi, Armelles, Gaspar, and Bi, Lei

Subjects
Physics - Optics
Abstract

Chiral nanophotonic devices are promising candidates for chiral molecules sensing, polarization diverse nanophotonics and display technologies. Active chiral nanophotonic devices, where the optical chirality can be controlled by an external stimulus has triggered great research interest. However, efficient modulation of the optical chirality has been challenging. Here, we demonstrate switching of the extrinsic chirality by applied magnetic fields in a magneto-plasmonic metasurface device based on a magneto-optical oxide material, Ce1Y2Fe5O12 (Ce:YIG). Thanks to the low optical loss and strong magneto-optical effect of Ce:YIG, we experimentally demonstrated a giant and continuous far-field circular dichroism (CD) modulation by applied magnetic fields from -0.65{\deg} to +1.9{\deg} at 950 nm wavelength under glancing incident conditions. The far field CD modulation is due to both magneto-optical circular dichroism and near-field modulation of the superchiral fields by applied magnetic fields. Finally, we demonstrate magnetic field tunable chiral imaging in millimeter-scale magneto-plasmonic metasurfaces fabricated using self-assembly. Our results provide a new way for achieving planar integrated, large-scale and active chiral metasurfaces for polarization diverse nanophotonics.

Published
2019

4. Active photonic platforms for the mid-infrared to the THz regime using spintronic structures

Author

Armelles Gaspar and Cebollada Alfonso

Subjects
active photonics, infrared and thz spectral range, magneto refractive, magnetic fields, metasurfaces, nanostructures, photonics, plasmonics, spintronics, Physics, QC1-999
Abstract

Spintronics and Photonics constitute separately two disciplines of huge scientific and technological impact. Exploring their conceptual and practical overlap offers vast possibilities of research and a clear scope for the corresponding communities to merge and consider innovative ideas taking advantage of each other’s potentials. As an example, here we review the magnetic field modification of the optical response of photonic systems fabricated out of spintronic materials, or in which spintronic components are incorporated. This magnetic actuation is due to the Magneto Refractive Effect (MRE), which accounts for the change in the optical constants of a spintronic system due to the magnetic field induced modification of the electrical resistivity. Due to the direct implication of conduction electrons in this phenomenon, this change in the optical constants covers from the mid-infrared to the THz regime. After introducing the non-expert reader into the spintronic concepts relevant to this work, we then present the MRE exhibited by a variety of spintronic systems, and finally show the different applications of this property in the generation of active spintronic-photonic platforms.

Published
2020
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6. Broad band infrared modulation using spintronic-plasmonic metasurfaces

Author

Armelles Gaspar, Bergamini Luca, Zabala Nerea, González María Ujué, García Fernando, Alvaro Raquel, Aizpurua Javier, and Cebollada Alfonso

Subjects
plasmonics, active metasurfaces, giant magnetoresistance (gmr), spintronics, slits, Physics, QC1-999
Abstract

We present magnetic field induced modulation of the optical response of slit plasmonic metasurfaces fabricated out of giant magnetoresistance/spintronic materials in the 2–17 μm spectral range of the spectrum. The modulation of the slit plasmonic modes is due to the modification of the electrical resistivity (and, in turn, of the optical constants) induced by the application of an external magnetic field. This modulation is found to continuously increase both with the slit concentration and with the slit resonance wavelength, with a prospective further increase for wavelengths of up to 60–80 μm. The direct fabrication and implementation of the modulation setup opens a competitive route for the development of active plasmonic metasurfaces in a wide spectral range.

Published
2019
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8. Multiresonant plasmon excitation in slit antennas on metallic and hyperbolic metamaterials

Author

Comunidad de Madrid, Ministerio de Economía y Competitividad (España), Consejo Superior de Investigaciones Científicas (España), European Commission, European Research Council, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Armelles, Gaspar, Domínguez-Vázquez, José María, Conca, Andrés, Alvaro, Raquel, Cebollada, Alfonso, Martín-González, Marisol, Comunidad de Madrid, Ministerio de Economía y Competitividad (España), Consejo Superior de Investigaciones Científicas (España), European Commission, European Research Council, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España), Armelles, Gaspar, Domínguez-Vázquez, José María, Conca, Andrés, Alvaro, Raquel, Cebollada, Alfonso, and Martín-González, Marisol

Abstract

A comparative study of the optical properties of random and ordered arrays of metallic and hyperbolic slit antennas is presented. The metallic slits are fabricated on Au layers, whereas the hyperbolic ones are fabricated on Au/MgO multilayers. The random arrays show, for both types of antennas, similar slit plasmon resonances whose positions depend on the internal structure of the supporting layer. On the other hand, the spectra of the ordered arrays of the hyperbolic slits present additional resonances related to the excitation of Bloch plasmon polaritons in the hyperbolic layer. By varying the slit length and periodicity, an analysis of the interaction between slit localized resonance and Bloch plasmon polaritons is also presented.

Published
2023

10. A novel vibrational spectroscopy using spintronic–plasmonic antennas: Magneto-refractive surface-enhanced infrared absorption.

Author

Armelles, Gaspar, Bergamini, Luca, Cebollada, Alfonso, Zabala, Nerea, and Aizpurua, Javier

Subjects
*INFRARED absorption, *MOLECULAR vibration, *LIGHT transmission, *SPECTROMETRY, *INFRARED spectroscopy, *ANTENNAS (Electronics)
Abstract

We present experimental and theoretical results of the molecular sensing performance of a novel platform based on magnetic modulation of surface-enhanced infrared absorption spectroscopy. For this, we study the effect that molecular infrared vibrations of a PMMA layer have on the optical and magneto-refractive response of spintronic antennas. Specifically, a periodic array of rods is fabricated from giant-magneto-resistance Au/Ni81Fe19 metallic multilayers, and the effect of depositing a layer of PMMA on top of the array is investigated from both experimental and theoretical points of view. We find that the relative changes induced by the infrared vibrations of PMMA on the magneto-refractive signal are larger than the relative changes induced on the optical transmission. This result indicates that the magneto-refractive response is more sensitive to the excitation of molecular vibrations than the optical response and fosters the development of a novel type of an infrared sensing technique based on spintronic antennas: Magneto-Refractive Surface-Enhanced Infrared Absorption (SEIRA) Spectroscopy. [ABSTRACT FROM AUTHOR]

Published
2021
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14. Plasmon Resonances in 1D Nanowire Arrays and 3D Nanowire Networks of Topological Insulators and Metals.

Author

Caballero-Calero, Olga, Ruiz-Clavijo, Alejandra, Manzano, Cristina V., Martín-González, Marisol, and Armelles, Gaspar

Subjects
TOPOLOGICAL insulators, NANOWIRES, THERMOELECTRIC power, RESONANCE, THERMOELECTRIC materials, ALUMINUM oxide
Abstract

The 1D nanowire arrays and 3D nanowire networks of topological insulators and metals have been fabricated by template-assisted deposition of Bi2Te3 and Ni inside anodic aluminum oxide (AAO) templates, respectively. Despite the different origins of the plasmon capabilities of the two materials, the results indicate that the optical response is determined by plasmon resonances, whose position depends on the nanowire interactions and material properties. Due to the thermoelectric properties of Bi2Te3 nanowires, these plasmon resonances could be used to develop new ways of enhancing thermal gradients and their associated thermoelectric power. [ABSTRACT FROM AUTHOR]

Published
2023
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16. A Novel Vibrational Spectroscopy Using Spintronic-Plasmonic Antennas: Magneto-Refractive Surface-Enhanced Infrared Absorption

Author

Electricidad y electrónica, Física de materiales, Elektrizitatea eta elektronika, Materialen fisika, Armelles, Gaspar, Bergamini, Luca, Cebollada, Alfonso, Zabala Unzalu, Miren Nerea, Aizpurua Iriazabal, Francisco Javier, Electricidad y electrónica, Física de materiales, Elektrizitatea eta elektronika, Materialen fisika, Armelles, Gaspar, Bergamini, Luca, Cebollada, Alfonso, Zabala Unzalu, Miren Nerea, and Aizpurua Iriazabal, Francisco Javier

Abstract

We present experimental and theoretical results of the molecular sensing performance of a novel platform based on magnetic modulation of surface-enhanced infrared absorption spectroscopy. For this, we study the effect that molecular infrared vibrations of a PMMA layer have on the optical and magneto-refractive response of spintronic antennas. Specifically, a periodic array of rods is fabricated from giant-magneto-resistance Au/Ni81Fe19 metallic multilayers, and the effect of depositing a layer of PMMA on top of the array is investigated from both experimental and theoretical points of view. We find that the relative changes induced by the infrared vibrations of PMMA on the magneto-refractive signal are larger than the relative changes induced on the optical transmission. This result indicates that the magneto-refractive response is more sensitive to the excitation of molecular vibrations than the optical response and fosters the development of a novel type of an infrared sensing technique based on spintronic antennas: Magneto-Refractive Surface-Enhanced Infrared Absorption (SEIRA) Spectroscopy.

Published
2021

23. Switching the Optical Chirality in Magnetoplasmonic Metasurfaces Using Applied Magnetic Fields

Author

Qin, Jun, primary, Deng, Longjiang, additional, Kang, Tongtong, additional, Nie, Lixia, additional, Feng, Huayu, additional, Wang, Huili, additional, Yang, Run, additional, Liang, Xiao, additional, Tang, Tingting, additional, Shen, Jian, additional, Li, Chaoyang, additional, Wang, Hanbin, additional, Luo, Yi, additional, Armelles, Gaspar, additional, and Bi, Lei, additional

Published
2020
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38. Magnetoplasmonics: Magnetoplasmonic Nanorings as Novel Architectures with Tunable Magneto‐optical Activity in Wide Wavelength Ranges (Advanced Optical Materials 7/2014)

Author

Feng, Hua Yu, primary, Luo, Feng, additional, Kekesi, Renata, additional, Granados, Daniel, additional, Meneses‐Rodríguez, David, additional, García, Jorge M., additional, García‐Martín, Antonio, additional, Armelles, Gaspar, additional, and Cebollada, Alfonso, additional

Published
2014
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42. Femtosecond surface plasmon interferometry with gold nanostructures

Author

Massachusetts Institute of Technology. Department of Chemistry, Temnov, Vasily V., Nelson, Keith Adam, Armelles, Gaspar, Cebollada, Alfonso, Thomay, Tim, Leitenstorfer, Alfred, Bratschitsch, Rudolf, Massachusetts Institute of Technology. Department of Chemistry, Temnov, Vasily V., Nelson, Keith Adam, Armelles, Gaspar, Cebollada, Alfonso, Thomay, Tim, Leitenstorfer, Alfred, and Bratschitsch, Rudolf

Abstract

We measure the ultrafast electron dynamics in gold via ultrafast surface plasmon interferometry. A new plasmonic microinterferometer with tilted slit-groove pair is used to unambiguously determine changes of real and imaginary parts of the dielectric function.

Published
2013

43. Spectral dependence of the magnetic modulation of surface plasmon polaritons in noble/ferromagnetic/noble metal films

Author

Massachusetts Institute of Technology. Department of Chemistry, Temnov, Vasily V., Armelles, Gaspar, Bratschitsch, Rudolf, Leitenstorfer, Alfred, Martin-Becerra, Diana, Thomay, Tim, Garcia-Martin, Antonio, González, María Ujué, Massachusetts Institute of Technology. Department of Chemistry, Temnov, Vasily V., Armelles, Gaspar, Bratschitsch, Rudolf, Leitenstorfer, Alfred, Martin-Becerra, Diana, Thomay, Tim, Garcia-Martin, Antonio, and González, María Ujué

Abstract

The magnetic field is an interesting candidate for the development of active plasmonic devices as it is able to modify the surface plasmon polariton (SPP) wave vector. Both real and imaginary parts of the SPP wave vector are affected. Here, we have experimentally determined the contribution of both modulations in the spectral range λ[subscript 0]=500–1000 nm for magnetoplasmonic systems consisting of noble/ferromagnetic/noble multilayered metal films. We have seen that the real part usually exceeds the imaginary one, but in the longer wavelength range the contribution of the imaginary part cannot be neglected. We have analyzed the spectral dependency of the modulation, and we conclude that it is dominated by the evolution of the SPP properties with wavelength and not the magneto-optical parameter. A figure of merit including modulation and propagation distance is also studied for the three ferromagnetic metals, Fe, Co, and Ni., European Union (NMP3-SL- 2008-214107-Nanomagma), Spain. Ministerio de Ciencia e Innovación (MICINN) (“MAPS” MAT2011-29194-C02-01), Spain. Ministerio de Ciencia e Innovación (MICINN) (“MAGPLAS” MAT2008-06765- C02-01/NAN), Spain. Ministerio de Ciencia e Innovación (MICINN) (“FUNCOAT” CONSOLIDER INGENIO 2010 CSD2008-00023), Madrid (Spain : Region) ("MICROSERES-CM” S2009/TIC-1476), Deutsche Forschungsgemeinschaft (DFG)

Published
2012

44. Magneto-optical manipulation of surface plasmons in gold/ferromagnetic/gold multilayer films

Author

Massachusetts Institute of Technology. Department of Chemistry, Temnov, Vasily V., Woggon, U., Guzatov, D., Armelles, Gaspar, Cebollada, Alfonso, Garcia-Martin, Antonio, Garcia-Martin, J. M., Thomay, T., Leitenstorfer, Alfred, Bratschitsch, Rudolf, Massachusetts Institute of Technology. Department of Chemistry, Temnov, Vasily V., Woggon, U., Guzatov, D., Armelles, Gaspar, Cebollada, Alfonso, Garcia-Martin, Antonio, Garcia-Martin, J. M., Thomay, T., Leitenstorfer, Alfred, and Bratschitsch, Rudolf

Abstract

Modulation of the surface plasmon wave vector in composite gold/cobalt/gold multilayer films due to periodic magnetization switching in cobalt is observed with a tilted slit-groove microinterferometer.

Published
2011

45. Femtosecond surface plasmon interferometry

Author

Massachusetts Institute of Technology. Department of Chemistry, Nelson, Keith Adam, Temnov, Vasily V., Armelles, Gaspar, Cebollada, Alfonso, Thomay, Tim, Leitenstorfer, Alfred, Bratschitsch, Rudolf, Massachusetts Institute of Technology. Department of Chemistry, Nelson, Keith Adam, Temnov, Vasily V., Armelles, Gaspar, Cebollada, Alfonso, Thomay, Tim, Leitenstorfer, Alfred, and Bratschitsch, Rudolf

Abstract

We demonstrate femtosecond plasmonic interferometry with a novel geometry. The plasmonic microinterferometer consists of a tilted slit-groove pair. This arrangement allows for (i) interferometric measurements at a single wavelength with a single microinterferometer and (ii) unambiguous discrimination between changes in real and imaginary parts of the metal dielectric function. The performance is demonstrated by monitoring the sub-picosecond dynamics of hot electrons in gold., Deutsche Forschungsgemeinschaft (TE770/1), National Science Foundation (U.S.) (CHE-0616939), National Science Foundation (U.S.) (CHE-0507147), European Commission (EU Network of Excellence ”PhOREMOST”), European Commission (EU Network of Excellence NMP3-SL-2008-214107-Nanomagma), European Commission (FUNCOAT CONSOLIDER INGENIO 2010 CSD2008-00023), European Commission (MAGPLAS MAT2008-06765-C02-01/NAN), European Commission (NANOMAGNETCMS- 0505/MAT/0194), European Commission (MICROSERES S-0505/TIC/0191)

Published
2011

49. Magnetic field control and wavelength tunability of SPP excitations using Al2O3/SiO2/Fe structures.

Author

Terunori Kaihara, Hiromasa Shimizu, Cebollada, Alfonso, and Armelles, Gaspar

Subjects
MAGNETIC fields, WAVELENGTHS, PLASMONS (Physics), POLARITONS, FERROMAGNETIC materials
Abstract

Here, we show the high wavelength tunability and magnetic field modulation of surface plasmon polaritons (SPPs) of a waveguide mode that Double-layer Dielectrics and Ferromagnetic Metal, Al2O2/SiO2/Fe, trilayer structures exhibit when excited in the Otto configuration of attenuated total reflection setup. First by modeling, and then experimentally, we demonstrate that it is possible to tune the wavelength at which the angular dependent reflectance of these structures reaches its absolute minimum by simply adjusting the SiO2 intermediate dielectric layer thickness. This precise wavelength corresponds to the cut-off condition of SPPs' waveguide mode supported by the proposed structure, and it can be then switched between two values upon magnetization reversal of the Fe layer. In this specific situation, a large enhancement of the transverse magneto-optical effect is also obtained. [ABSTRACT FROM AUTHOR]

Published
2016
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