Related papers: Multi-color broadband visible light source via thr…
We consider a line-shape of magnetoexciton photoluminescence from quantum wells when the disorder is sufficiently small. In this case the phonon-assisted optical transitions become important for the line formation. We study both inter-band…
Within the framework of our program of assessment of the nature of unidentified or poorly known INTEGRAL sources, we present here spectroscopy of optical objects, selected through positional cross-correlation with soft X-ray detections…
In the context of AGN unification scheme rapid variability properties play an important role in understanding any intrinsic differences between sources in different classes. In this respect any clue based on spectral properties will be very…
Thermal emission is a ubiquitous electromagnetic wave with an extreme broad spectrum in nature, and controlling thermal emission can be used to develop low-cost and convenient infrared light sources with wavelength tunable in a wide range…
A microscopic theory for the generation and propagation of coherent LA phonons in pseudomorphically strained wurzite (0001) InGaN/GaN multi-quantum well (MQW) p-i-n diodes is presented. The generation of coherent LA phonons is driven by…
Silicon's inherently indirect bandgap severely limits its radiative efficiency, posing a fundamental challenge to the development of practical silicon-based light sources. While strategies such as nanoscale confinement of electrons and…
We analyze theoretically a possibility of the superradiant emission (SR) in GaN-based quantum well (QW) laser heterostructures. Our model is based on travelling wave Maxwell-Bloch equations predicts building up of macroscopic coherences in…
We report on structural and optical properties of InGaN/GaN thin films, with a 0.46o misalignment between the surface and the (0001) plane, which were grown by metal-organic chemical vapor deposition (MOCVD) on 0.34o miscut sapphire…
In the time domain, the radio sky in particular along the Galactic plane direction may vary significantly because of various energetic activities associated with stars, stellar and supermassive black holes. Using multi-epoch Very Large…
I review here some of the main observational features in microquasars and AGNs as sources of high-energy gamma-rays as well as some of the current models that try to explain the emission in the gamma-ray domain.
A new on-chip light source configuration has been proposed, which utilizes the interaction between microwave and a dielectric nanopillar array to generate a periodic electromagnetic near field, and applies periodic transverse acceleration…
Single lateral InGaAs quantum dot molecules have been embedded in a planar micro-cavity in order to increase the luminescence extraction efficiency. Using a combination of metal-organic vapor phase and molecular beam epitaxy samples could…
Attosecond light sources based on high-order harmonic generation (HHG) constitute to date the only table-top solution for producing coherent broadband radiation covering the spectral range from the extreme ultraviolet to the soft X-rays.…
We synthesize and study the structural and optical properties of nanocrystalline graphene monofluoride and graphite monofluoride, which are carbon-based wide bandgap materials. Using laser excitations 2.41 - 5.08 eV, we identify six…
The recent progress in formation of two-dimensional (2D) GaN by a migration-enhanced encapsulated technique opens up new possibilities for group III-V 2D semiconductors with a band gap within the visible energy spectrum. Using…
Optical metamaterials (OMs) at visible wavelengths have been extensively developed. OMs reported recently are all composed of periodic structure, and fabricated by top-down approaches. Here demonstrated are the colored visible light…
The primary challenge in silicon photonics is achieving efficient luminescence in the communication band, crucial for its large-scale application. Despite significant efforts, silicon light sources still suffer from low efficiency and…
Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess…
A global view is given of how emission lines have been, and may in the future, be used to enhance our understanding of AGN. Lines from the microwave to the X-ray bands all contribute. Although we have a deep understanding of the physical…
A design strategy for achieving broadband optical gain in GaSb-based semiconductor amplifiers operating beyond 2 \mu m is presented. By employing asymmetric GaInSb/AlGaAsSb quantum wells (QWs) of varying thicknesses, a flat and wide gain…