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Recent developments in the area of resonant dielectric nanostructures have created attractive opportunities for concentrating and manipulating light at the nanoscale and the establishment of the new exciting field of all-dielectric nanophotonics. Transition metal dichalcogenides (TMDCs) with nanopatterned surfaces are especially promising for these tasks. Still, the fabrication of these structures requires sophisticated lithographic processes, drastically complicating application prospects. To bridge this gap and broaden the application scope of TMDC nanomaterials, we report here femtosecond laser-ablative fabrication of water-dispersed spherical TMDC (MoS2 and WS2) nanoparticles (NPs) of variable size (5 to 250 nm). Such NPs demonstrate exciting optical and electronic properties inherited from TMDC crystals, due to preserved crystalline structure, which offers a unique combination of pronounced excitonic response and high refractive index value, making possible a strong concentration of electromagnetic field in the NPs. Furthermore, such NPs offer additional tunability due to hybridization between the Mie and excitonic resonances. Such properties bring to life a number of nontrivial effects, including enhanced photoabsorption and photothermal conversion. As an illustration, we demonstrate that the NPs exhibit a very strong photothermal response, much exceeding that of conventional dielectric nanoresonators based on Si. Being in a mobile colloidal state and exhibiting superior optical properties compared to other dielectric resonant structures, the synthesized TMDC NPs offer opportunities for the development of next-generation nanophotonic and nanotheranostic platforms, including photothermal therapy and multimodal bioimaging.

Semiconductor nanoparticles (SNPs), such as quantum dots (QDs) and core/shell nanoparticles, have proven to be promising candidates for the development of next‐generation technologies, including light‐emitting diodes (LEDs), liquid crystal displays (LCDs) and solar concentrators. Typically, these applications use a sub‐micrometer‐thick film of SNPs to realize photoluminescence. However, our current knowledge on how this thin SNP layer affects the optical efficiency remains incomplete. In this work, we demonstrate how the thickness of the photoluminescent layer governs the direction of the emitted light. Our theoretical and experimental results show that the emission is fully outcoupled for sufficiently thin films (monolayer of SNPs), whereas for larger thicknesses (larger than one tenth of the wavelength) an important contribution propagates along the film that acts as a planar waveguide. These findings serve as a guideline for the smart design of diverse QD‐based systems, ranging from LEDs, where thinner layers of SNPs maximize the light outcoupling, to luminescent solar concentrators, where a thicker layer of SNPs will boost the efficiency of light concentration. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

This thesis addresses three different topics on the interaction between light and matter in open quantum systems. The first topic concerns two-dimensional spectroscopy and the spectral contributions from different nonlinear action signals with a focus on how to differentiate between them. The second topic concerns the thermalization of excited electrons in hot-carrier solar cells with a focus on how to optimize the quantum efficiency of extraction.The third topic concerns quantum heat engines with two related foci: the fundamental nature of heat and work flow in quantum thermodynamics, as well as the relation between quantum-coherent dynamics and a thermodynamic quantum advantage compared to classical model systems. The thesis comprises four papers.In Paper I we identify the qualitative differences between the ''true'' nonlinear spectral contributions and nonlinear incoherent mixing signals.In Paper II we model the thermalization of excited carriers in a hot-carrier solar cell and quantify the second order Coulomb scattering in the systems.In Paper III we compare two different definitions of work and heat flow in a three-level maser and salvage the second law of thermodynamics in the conventional definitions of work and heat.In Paper IV we investigate the advantage of a quantum model over its classical counterpart in terms of the Thermodynamic Uncertainty Relation and illustrate how the steady-state quantum coherence is insufficient to describe the nature of this advantage.

Photon absorption and emission play a key role in our understanding of how light interacts with matter. An attractive system to explore these processes are semiconductor nanoparticles (SNP) with their distinguishable photoluminescence, which makes them widely applied in optoelectronics, laser technology, and biophotonics. In current implementations of SNP, there is only partial control over anisotropy in absorption or in emission, which limits their applicability in photonics. An emerging strategy to attain a certain degree of anisotropy is to embed a quantum dot in semiconductor shell structure. Here, we report how designing the shell geometry and the position of the quantum dot enables extended control over the anisotropy in absorption and emission by a core/shell nanoparticle in a solvent. Based on the dielectric effect, our approach provides an accessible route to achieve sharply contrasting anisotropies that may even have an opposite sign. Using this unique feature, we propose cross particles to transform unpolarized blue light into polarized red and green light for liquid crystal backlights and thumbtack particles to absorb sunlight and efficiently emit photons in a solar concentrator. The strong anisotropic contrast between absorption and emission of SNP may advance energy-efficient technology, biodiagnostics, and quantum information, as well as offer new insights on light-matter interaction at the nanoscale. Copyright © 2019 American Chemical Society.

Nanomembranes represent a versatile novel building block in micro- and nanoelectromechanical systems, inspired by biological cell membranes. If built as quasi-2D multilayer metal-dielectric nanocomposites, they represent a natural choice for the use in plasmonics and optical metamaterials, ensuring a new degree of design freedom and thus a number of new applications. In this contribution we consider surface sculpting of two types of three-layer nanomembranes – metal-insulator-metal (MIM) and insulator-metal-insulator (IMI) structures. The geometry we analyze represents troughs with ellipsoidal profiles sculpted in the multilayer nanomembranes, simultaneously acting as plasmonic waveguides and ensuring tailoring of frequency dispersion of the plasmonic nanomembranes. We determine frequency dispersions of the scattering parameters for the simulated nanomembranes, as well as the spatial ditribution of the optical near fields in and around them, both evanescent (plasmon-polariton based) and propagating. To this purpose we utilize finite element method simulations. The obtained results show that our IMI structures exhibit a behavior similar to that of the EOT arrays, resulting in optical transparency of the structure for resonant plasmonic modes. On the other hand, MIM structures offer an excellent confinement of electromagnetic radiation within the dielectric layer. We conclude that both MIM and IMI channels allow for additional degrees of freedom in customization the nanomembrane evanescent fields, making a way to numerous potential applications.

Phase singularities can be created and annihilated, but always in pairs. With optical near-field measurements, we track singularities in random waves as a function of wavelength, and discover correlations between creation and annihilation events., QN/Kuipers Lab, QN/Quantum Nanoscience

Phase singularities are locations where light is twisted like a corkscrew, with positive or negative topological charge depending on the twisting direction. Among the multitude of singularities arising in random wave fields, some can be found at the same location, but only when they exhibit opposite topological charge, which results in their mutual annihilation. New pairs can be created as well. With near-field experiments supported by theory and numerical simulations, we study the persistence and pairing statistics of phase singularities in random optical fields as a function of the excitation wavelength. We demonstrate how such entities can encrypt fundamental properties of the random fields in which they arise., QN/Kuipers Lab, QN/Quantum Nanoscience

Phase singularities are locations where light is twisted like a corkscrew, with positive or negative topological charge depending on the twisting direction. Among the multitude of singularities arising in random wave fields, some can be found at the same location, but only when they exhibit opposite topological charge, which results in their mutual annihilation. New pairs can be created as well. With near-field experiments supported by theory and numerical simulations, we study the persistence and pairing statistics of phase singularities in random optical fields as a function of the excitation wavelength. We demonstrate how such entities can encrypt fundamental properties of the random fields in which they arise., QN/Kuipers Lab, QN/Quantum Nanoscience

Phase singularities can be created and annihilated, but always in pairs. With optical near-field measurements, we track singularities in random waves as a function of wavelength, and discover correlations between creation and annihilation events., QN/Kuipers Lab, QN/Quantum Nanoscience

This work is a part of the SunTune project which addresses efficiency improvements of solar modules by manipulating the spectrum of sunlight to better match the range of efficient current generation in silicon solar cells. Photons with energies below the band gap energy of silicon (<1.1eV) are (up)converted into photons with higher energies through absorption in rare earth ions (Er3+) followed by radiative decay.This process converts otherwise non-absorbed long wavelength photos to shorter wavelength photons able to bridge the band gap energy and contribute to the energy generation of the solar modules. The upconversion process is naturally inefficient,and without any enhancement of the incident light, the process is negligible. The probability for upconversion can be increased by focusing the incident light into areas doped with Er3+ions, using optimized nanoparticles placed into or near these areas. Studies have shown that the intensity of the upconverted light is proportional to the intensity of the incident light raised to some power, n, [1]. Experimentally n is found to be 1.5 and the light intensity is proportional to the square of the electric field norm, |E|2. We aim to enhance the incident light using topology optimized nanoparticles. Here, the distribution of nanoparticle material is optimized to enhance |E|3 in a thin Er3+ doped TiO2 film. Topology optimization has previously proven successful for optimizing wave propagation in acoustics [2] and electromagnetics [3,4]. The governing physics is modeled classically using Maxwell equations in the frequency domain.The model is excited by an incoming plane wave with a wave length, within the near-infrared absorption band of Er3+ (1480nm -1560nm).

The detailed investigation has been made of the lens effect in plane multilayered metal-dielectric structures (Ag-TiO2). The optical scheme of the lens has been studied with the radiation focusing in free space. The transfer function is calculated, where the phase profile determines definitely the possibility of focusing. The condition for far-field image formation is found using a flat lens. This condition is used for a numerical simulation of several lens designs with a various number of metal layers. It is found that considered flat lenses have close to limiting angular aperture and therefore the subwavelength resolution. It is established that at increase of a number of metal layers the object and image distances grow.

The detailed investigation has been made of the lens effect in plane multilayered metal-dielectric structures (Ag-TiO2). The optical scheme of the lens has been studied with the radiation focusing in free space. The transfer function is calculated, where the phase profile determines definitely the possibility of focusing. The condition for far-field image formation is found using a flat lens. This condition is used for a numerical simulation of several lens designs with a various number of metal layers. It is found that considered flat lenses have close to limiting angular aperture and therefore the subwavelength resolution. It is established that at increase of a number of metal layers the object and image distances grow.

The detailed investigation has been made of the lens effect in plane multilayered metal-dielectric structures (Ag-TiO2). The optical scheme of the lens has been studied with the radiation focusing in free space. The transfer function is calculated, where the phase profile determines definitely the possibility of focusing. The condition for far-field image formation is found using a flat lens. This condition is used for a numerical simulation of several lens designs with a various number of metal layers. It is found that considered flat lenses have close to limiting angular aperture and therefore the subwavelength resolution. It is established that at increase of a number of metal layers the object and image distances grow.

We study the optical response of various nanojunction solar cell architectures and examine how various cylindrical arrangements of emitter, base, glass and transparent conductor affect reflection and absorption of incident light. The photogeneration profiles of such nano-architectures are cylindrically asymmetric, varying axially, radially and azimuthally within the wavelength band investigated. Such 3D profiles require 3D device models for accurate device analysis. The extended nanojunction configuration was examined in more detail, as this design is known to have superior performance. The particular design consists ofnanostructured glass and a superstrate arrangement of the other device elements.

Diese Arbeit beschreibt eine ausfŸhrliche Untersuchung der physikalischen Eigenschaften von Mikrokugelresonatoren aus Quarzglas. Diese Resonatoren unterstŸtzen sogennante whispering-gallery Moden (WGM), die GŸten so hoch bis 109 bieten. Als experimentelle Hilfsmittel wurden ein Nahfeld- und ein Konfokalmikroskop benutzt, um die Struktur der Moden bezŸglich der Topographie des Resonators eindeutig zu identifizieren, oder um einzelne Quantenemitter zu detektieren und anzuregen. Die resonante †berhšhung des elektromagnetischen Feldes in den Moden des Resonators wurde ausgenutzt, um stimulierte Raman-Streuung mit extrem niedrigem Schwellenwert im Quarzglas zu beobachten. Ein Rekordschwellenwert von 4.5 Mikrowatts wurde gemessen. Mittels einer Nahfeldsonde wurde die Modenstruktur des Mikro-Ramanlasers gemessen. Mikroresonatoren stellen einen Grundbaustein der Resonator-Quantenelektrodynamik dar. In dieser Arbeit wurde die Kopplung von einem einzelnen strahlenden Dipol an die WGM sowohl theoretisch als auch experimentell untersucht. Die kontrollierte Kopplung von einem einzelnen Nanoteilchen an die WGM eines Mikrokugelresonators wurde nachgewiesen. Erste Ergebnisse in der Kopplung eines einzelnen Emitters an die Moden des Resonators wurden erzielt. Die resonante Wechselwirkung mit Resonatormoden wurde ausgenutzt, um den Photonentransfer zwischen zwei Nanoteilchen dramatisch zu verstŠrken. Schlie§lich wurde die bislang unbeachtete Analogie zwischen dem Quantensystem eines einzelnen Emitters in Wechselwirkung mit einer einzelnen Resonatormode und dem klassischen System zweier gekoppelten Moden experimentell untersucht. Es wurde bewiesen, wie die aus der Resonatorquantenelektrodynamik bekannten Kopplungsregime der starken und schwachen Kopplung in Analogie auch an einem klassischen System beobachtet werden kšnnen. Der †bergang von schwacher zu starker Kopplung wurde beobachtet, und bislang gemessene unerwartet hohe Kopplungsraten konnten einfach erklŠrt werden., This work presents an extensive study of the physical properties of silica microsphere resonators, which support whispering-gallery modes (WGMs). These modes feature Q-factors as high as 109 corresponding to a finesse of 3 millions for spheres with a diameter of about 80 micrometers. These are to date among the highest available Q-factors, leading to cavity lifetimes of up to few microseconds. A near-field microscope and a confocal microscope are used as tools to unequivocally identify the mode structure related to the sphere topography, and for excitation and detection of single quantum emitters. The high field enhancement of the cavity modes is exploited to observe ultra-low threshold stimulated Raman scattering in silica glass. A record ultra-low threshold of 4.5 microwatts was recorded. The mode structure of the laser is investigated by means of a near-field probe, and the interaction of the probe itself with the lasing properties is investigated in a systematic way. Microcavities also one of the building blocks of Cavity QED. Here, the coupling of a radiative dipole to the whispering-gallery modes has been studied both theoretically and experimentally. The controlled coupling of a single nanoparticle to the WGMs is demonstrated, and first results in coupling a single quantum emitter to the modes of a microsphere are reported. The resonant interaction with these modes is exploited to enhance photon exchange between two nanoparticles. Finally a novel analogy between a system composed of a single atom interacting with one cavity mode on one side and intramodal coupling in microsphere resonators induced by a near-field probe on the other side is presented and experimentally explored. The induced coupling regimes reflect the different regimes of weak and strong coupling typical of Cavity QED. The transition between the two coupling regimes is observed, and a previously observed unexpectedly large coupling rate is explained.

Diese Arbeit beschreibt eine ausfŸhrliche Untersuchung der physikalischen Eigenschaften von Mikrokugelresonatoren aus Quarzglas. Diese Resonatoren unterstŸtzen sogennante whispering-gallery Moden (WGM), die GŸten so hoch bis 109 bieten. Als experimentelle Hilfsmittel wurden ein Nahfeld- und ein Konfokalmikroskop benutzt, um die Struktur der Moden bezŸglich der Topographie des Resonators eindeutig zu identifizieren, oder um einzelne Quantenemitter zu detektieren und anzuregen. Die resonante †berhšhung des elektromagnetischen Feldes in den Moden des Resonators wurde ausgenutzt, um stimulierte Raman-Streuung mit extrem niedrigem Schwellenwert im Quarzglas zu beobachten. Ein Rekordschwellenwert von 4.5 Mikrowatts wurde gemessen. Mittels einer Nahfeldsonde wurde die Modenstruktur des Mikro-Ramanlasers gemessen. Mikroresonatoren stellen einen Grundbaustein der Resonator-Quantenelektrodynamik dar. In dieser Arbeit wurde die Kopplung von einem einzelnen strahlenden Dipol an die WGM sowohl theoretisch als auch experimentell untersucht. Die kontrollierte Kopplung von einem einzelnen Nanoteilchen an die WGM eines Mikrokugelresonators wurde nachgewiesen. Erste Ergebnisse in der Kopplung eines einzelnen Emitters an die Moden des Resonators wurden erzielt. Die resonante Wechselwirkung mit Resonatormoden wurde ausgenutzt, um den Photonentransfer zwischen zwei Nanoteilchen dramatisch zu verstŠrken. Schlie§lich wurde die bislang unbeachtete Analogie zwischen dem Quantensystem eines einzelnen Emitters in Wechselwirkung mit einer einzelnen Resonatormode und dem klassischen System zweier gekoppelten Moden experimentell untersucht. Es wurde bewiesen, wie die aus der Resonatorquantenelektrodynamik bekannten Kopplungsregime der starken und schwachen Kopplung in Analogie auch an einem klassischen System beobachtet werden kšnnen. Der †bergang von schwacher zu starker Kopplung wurde beobachtet, und bislang gemessene unerwartet hohe Kopplungsraten konnten einfach erklŠrt werden., This work presents an extensive study of the physical properties of silica microsphere resonators, which support whispering-gallery modes (WGMs). These modes feature Q-factors as high as 109 corresponding to a finesse of 3 millions for spheres with a diameter of about 80 micrometers. These are to date among the highest available Q-factors, leading to cavity lifetimes of up to few microseconds. A near-field microscope and a confocal microscope are used as tools to unequivocally identify the mode structure related to the sphere topography, and for excitation and detection of single quantum emitters. The high field enhancement of the cavity modes is exploited to observe ultra-low threshold stimulated Raman scattering in silica glass. A record ultra-low threshold of 4.5 microwatts was recorded. The mode structure of the laser is investigated by means of a near-field probe, and the interaction of the probe itself with the lasing properties is investigated in a systematic way. Microcavities also one of the building blocks of Cavity QED. Here, the coupling of a radiative dipole to the whispering-gallery modes has been studied both theoretically and experimentally. The controlled coupling of a single nanoparticle to the WGMs is demonstrated, and first results in coupling a single quantum emitter to the modes of a microsphere are reported. The resonant interaction with these modes is exploited to enhance photon exchange between two nanoparticles. Finally a novel analogy between a system composed of a single atom interacting with one cavity mode on one side and intramodal coupling in microsphere resonators induced by a near-field probe on the other side is presented and experimentally explored. The induced coupling regimes reflect the different regimes of weak and strong coupling typical of Cavity QED. The transition between the two coupling regimes is observed, and a previously observed unexpectedly large coupling rate is explained.

We demonstrate that efficient adiabatic nanofocusing of plasmons can be achieved using a sharp metal wedge (thin tapered film) on a dielectric substrate. It is shown that the quasi-symmetric (with respect to the charge distribution across the wedge) plasmon mode can experience infinite adiabatic slowing down with both its phase and group velocities reducing to zero as the plasmon propagates towards the tip of the wedge. Conditions for strong local field enhancement near the tip are determined and analyzed. In particular, it is demonstrated that the electric field in the plasmon experiences much stronger local enhancement than the magnetic field. Two distinct asymptotic regimes with the electric field amplitude approaching either zero or infinity at the tip of the wedge (tapered film) are described. The results are compared to adiabatic nanofocusing of plasmons by metallic V-grooves and sharp metal wedges in a uniform dielectric.

We demonstrate that during plasmon nano-focusing in a tapered gap (V-groove), local electric field experiences much stronger enhancement than the magnetic field. Two distinct asymptotic regimes are found near the tip of the groove: the electric field approaches either zero or infinity when dissipation is above or below a critical level (at a fixed taper angle), or taper angle is smaller or larger than a critical angle (at a fixed level of dissipation). Tapered gaps are shown to be the best option for achieving maximal field enhancement, compared to nano-wedges and tapered rods. An optimal taper angle is determined.

Owing to their surface plasmon-based operation, arrays of subwavelength holes show extraordinary electromagnetic transmission and intense field localizations of several orders of magnitude. Thus they were proposed as the basic building blocks for a number of applications utilizing the enhancement of nonlinear optical effects. We designed and simulated nanometer-sized subwavelength holes using an analytical approach. In our experiments we used the scanning probe method for nanolithographic fabrication of subwavelength hole arrays in silver layers sputtered on a positive photoresist substrate. We fabricated ordered nanohole patterns with different shapes, dispositions and proportions. The smallest width was about 60 nm. We characterized the fabricated samples by atomic force microscopy., Zahvaljujući tome što im je funkcionisanje zasnovano na površinskim plazmonima, kod matrica šupljina subtalasnih dimenzija dolazi do izuzetno povećane elektromagnetske transmisije i intenzivne lokalizacije polja od nekoliko redova veličine. Zbog toga su takve strukture predložene kao osnovni gradivni blokovi za raznovrsne primene kod kojih se koristi pojačanje nelinearnih efekata. Koristeći analitički pristup, u ovom radu projektovali smo i simulirali matrice subtalasnih šupljina nanometarskih dimenzija. U našim eksperimentima koristili smo metodu skanirajuće sonde za nanolitografsku izradu matrica subtalasnih šupljina u srebrnim slojevima spaterovanim na supstratu od fotootpornog pozitiva. Napravili smo pravilno raspoređene nanošupljine različitih oblika, rasporeda i dimenzija, pri čemu je širina najmanjih bila oko 60 nm. Izrađene uzorke karakterisali smo AFM mikroskopijom.

Owing to their surface plasmon-based operation, arrays of subwavelength holes show extraordinary electromagnetic transmission and intense field localizations of several orders of magnitude. Thus they were proposed as the basic building blocks for a number of applications utilizing the enhancement of nonlinear optical effects. We designed and simulated nanometer-sized subwavelength holes using an analytical approach. In our experiments we used the scanning probe method for nanolithographic fabrication of subwavelength hole arrays in silver layers sputtered on a positive photoresist substrate. We fabricated ordered nanohole patterns with different shapes, dispositions and proportions. The smallest width was about 60 nm. We characterized the fabricated samples by atomic force microscopy., Zahvaljujući tome što im je funkcionisanje zasnovano na površinskim plazmonima, kod matrica šupljina subtalasnih dimenzija dolazi do izuzetno povećane elektromagnetske transmisije i intenzivne lokalizacije polja od nekoliko redova veličine. Zbog toga su takve strukture predložene kao osnovni gradivni blokovi za raznovrsne primene kod kojih se koristi pojačanje nelinearnih efekata. Koristeći analitički pristup, u ovom radu projektovali smo i simulirali matrice subtalasnih šupljina nanometarskih dimenzija. U našim eksperimentima koristili smo metodu skanirajuće sonde za nanolitografsku izradu matrica subtalasnih šupljina u srebrnim slojevima spaterovanim na supstratu od fotootpornog pozitiva. Napravili smo pravilno raspoređene nanošupljine različitih oblika, rasporeda i dimenzija, pri čemu je širina najmanjih bila oko 60 nm. Izrađene uzorke karakterisali smo AFM mikroskopijom.

Interferometric lithography, the interference of a small number of coherent optical beams, is a powerful technique for the fabrication of a wide array of samples. The techniques and limits of interferometric lithography are discussed with particular attention to the smallest scales achievable. With immersion techniques, the smallest pattern size for a single exposure is a half pitch of lamda/4n were lamda is the optical wavelength and n is the refractive index of the immersion material. Currently with a 193-nm excimer laser source and H2O immersion, this limiting dimension is 34 nm. With nonlinear spatial frequency multiplication techniques, this limit is extended by factors of 1/2, 1/3, etc.- extending well into the nanoscale regime. Interferometric lithography provides an inexpensive, large-area capability as a result of its parallelism. Imaging interferometric lithography provides an approach to arbitrary structures with comparable resolution. Imaging interferometric microscopy provides an alternative super-resolution technique with application to lithographic mask inspection. Numerous application areas include: nanoscale epitaxial growth for semiconductor heterostructures; nanofluidics for biological separations; nanophotonics including distributed feedback and distributed Bragg reflectors, 2D and 3D photonic crystals, metamaterials and negative refractive index materials for enhanced optical interactions.

This report describes the development of enabling mesoscale materials and development of new instrumentation and methodologies for nanoscale material characterization. The work involved the following eight separate efforts: 1. Use of Colloidal Array Photonic Materials for Photochemically and Photothermally Controllable Diffraction Devices; 2. Development of Methods to Fabricate Nanoscale and Mesoscale Enabling Materials such as Magnetically Anisotropic Spherical Particles; 3. Development of Methods to Fabricate Particles -with Chemically Anisotropic Surfaces; 4. Theoretical Determination of the Dependence of Photonic Crystal Diffraction on Crystal Dielectric Modulation and the Crystal Defect Structures; 5. Development of Methods to Direct, Control and Study the Self-Assembly of Ge/Si Quantum Dots; 6. Fabrication of Molecular Scale Shift Register Memories; 7. Development of a Nanoworkbench for Analysis, Manipulation and Excitation of Individual Nanostructures; and 8. Development of Instrumentation and Methodologies for Chemical Imaging of Nanoscale Surface Structures., Monitor: US Army Research, Development and Engineering Command, Natick Soldier Center, ATTN: AMSRD-NSC-SS-MA, Natick, MA.

This program has supported students working on developing a fundamental understanding of the quantum features of nano-optical structures in semiconductors. A number of published papers resulted including a report on the first observation of the Raman coherence in a semiconductor, and the first report of directly probing optical excitation based on the coherent nonlinear optical response using a near-field optical microscope.