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Carbon-based nanostructures have been the center of intense research and development for more than two decades now. Of these materials, graphene, a two-dimensional (2D) layered material system, has had a significant impact on science and technology in recent years after it was experimentally isolated in single layers in 2004. The recent emergence of other classes of two-dimensional (2D) layered systems...
The timely and accurate detection of threat contraband especially for ports-of-entry (e.g. harbors, bays, borders, airports) is an extremely critical problem of national security. The investigation of advanced techniques to reliably and accurately detect threats and reject non-threats is the major focus of this effort. The characterization of signal processing models based on xray transport physics...
The influence of compositional fluctuations of N in GaInNAs Quantum Well (QW) lasers has been studied using a rate equation model. These fluctuations can be treated as Quantum-Dot (QD)-like fluctuations at the Conduction Band Edge (CBE). The gain model includes the QW material gain derived using a Band Anti-Crossing (BAC) model and includes QD fluctuations in the conduction band. For low N, (N ∼ 1%),...
In this paper we present two examples of combining fluorescent nanoparticles with photonic materials. First, we present the results on new compound: nanodiamonds and silk. Second, we report on ZnO fluorescence, with ZnO nanoparticles obtained by Zn-ion implantation in silica.
In this paper we predict how a valence band excitation couples with TE-polarized THz radiation in a microcavity. This configuration would allow easier measurements of polaritons and antipolaritons without the need to grow the resonator in a slanted prism, as in usual TM mode, conduction band realizations.
A model of charge quantum tunneling percolation through a composite sample consisting of an ensemble of conducive nano-spheres embedded in a dielectric matrix. Some peculiarities arising from the insertion of tunneling processes into the general percolating framework are outlined. The related results may be used for optimizing the fabrication of electronic devices based on such composite materials.
This paper reviews the progress of III–V semiconductor technology for the application to photonic telecommunications and signal processing systems by focusing nanostructure materials and devices as well as monolithic/hybrid integration technologies for improving performance and functions. Also the role of combined use of nanostructure devices and integration technology is discussed for the development...
Light incident on a scattering medium is redistributed over transport channels that either transmit through or reflect from the medium. We perform experiments aiming at finding individual transport channels of extremely strongly scattering materials. A small number of transport channels in a scattering sample are open with transmission coefficient close to 1; field transmission mainly takes place...
For many optoelectronic applications, such as photodetection and light harvesting, it is highly desirable to identify materials in which an absorbed photon is efficiently converted to electronic excitations. The unique properties of graphene, such as its gapless band structure, flat absorption spectrum and strong electron-electron interactions, make it a highly promising material for efficient broadband...
Tunable, polarized, mono-energetic, gamma-ray (MEGa-ray) beams can be created via Compton scattering of pulsed lasers off of ultra-bright electron beams. Above 2 MeV, the peak brilliance of an optimized MEGa-ray source can exceed that of world's largest synchrotrons by more than 15 orders of magnitude. These narrow-divergence, laser-like, gamma-ray beams are enabling the pursuit of new nuclear science...
Probing of delicate systems demands high sensitivity from limited probe energy. Quantum optical techniques to beat the standard quantum limit (SQL) offer a practical advantage for these measurements. Here we report the first entanglement-enhanced measurement of a delicate material system [1]. We non-destructively probe an atomic spin ensemble by near-resonant Faraday rotation, a measurement that is...
PHOTON ENERGY introduced a new ps-laser “CEPHEUS” with pulse duration of 10ps and max. average power of 12W. The repetition rate can be set from single shot up to 500 kHz.
The field of quantum key distribution has made rapid advances in the past years. Networks of QKD links were implemented, commercial QKD systems are available and research systems have reached GHz repetition rates and distances beyond 200 km. Usually decoy protocols with attenuated laser light pulses are used, where the asymptotic key rate of a QKD system is proportional to the fraction of single photon...
Introduction: Nanostructures are used in various forms to increase light extraction from materials with a high refractive index [1,2]. Recently, photonic crystals (PhC) have been proposed to improve the light yield of scintillators used in high energy physics and medical imaging applications [3]. PhCs consisting of a thin slab with a periodically modulated refractive index serve to reduce total internal...
The study of light propagation and interaction with disordered systems represents one of the ultimate frontiers in research in Photonics [1-3]. In this invited contribution I will summarize my theoretical and experimental research activity in the field, discussing both geometrical disorder (i.e., random distribution of index of refraction) as well as wave disorder (i.e., quantum chaotic structures)...
The main objective of this paper is to increase the efficiency of the multi-junction solar cell. In general, the efficiency of the multi-junction solar cell depends upon various design parameters such as material type, thickness of the layers, doping concentration, type of texturing and thickness of anti-reflective coating. The performances of the solar cells are determined by using one-dimensional...
As one of the most competitive materials of the integrated optics, photonic crystals (PCs) have been investigated for more than 20 years since its conception was proposed. In this work, we established a novel structure of the bend waveguide which is composed of photonic crystal (PC) with triangular lattice of air-holes. By optimizing the bend structures, not only the transmission bandwidth of the...
Plasmonics is an exploding new field of science and technology in which the flow of light can be molded at the nanoscale using metallic nanostructures. This newly found ability is rapidly impacting every facet of optics and photonics and is enabling a myriad of exciting new technologies. Semiconductor nanophotonics has also seen tremendous recent progress in the development of high performance light...
The tutorial will introduce the mechanisms of materials modification by electronic excitation and will describe theoretical methods and models used for studying the behavior of atoms inside solids and at surfaces under laser excitation.
We examine numerically and experimentally photonic band-gaps in liquidlike two dimensional photonic materials. Subwavelength dielectric rods are randomly placed with Monte Carlo simulations, fabricated on silicon-on-insulator chips, and measured in near infrared wavelengths.
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