相关论文: Interband Light Absorption at a Rough Interface
The phenomenological boundary conditions for the envelope wave function, which is applicable for contacts of semiconductors with the rather different crystal symmetry are proposed. It is shown that the boundary conditions are determined by…
For semiconductors and semimetals possessing a narrow gap between bands with different parity, the dispersion of the dielectric function is explicitly evaluated in the infrared region. The imaginary part of the dielectric function has a…
We study light absorption by weakly rough metal surfaces with the roughness amplitude and correlation length smaller than the skin depth in metal. We develop a systematic perturbative approach for calculation of the absorptance in such…
Photons do not carry sufficient momentum to induce indirect optical transitions in semiconducting materials such as silicon, necessitating the assistance of lattice phonons to conserve momentum. Compared to direct bandgap semiconductors,…
Semiconductors are by now well-established targets for direct detection of MeV to GeV dark matter via scattering off electrons. We show that semiconductor targets can also detect significantly lighter dark matter via an absorption process.…
The optical properties of silicon can be greatly tuned by applying strain and opening new perspectives, particularly in applications where infrared is key. In this work, we use a recent model for the indirect light absorption of silicon and…
We study oblique incident light absorption in opaque media with rough surfaces. An analytical approach with modified boundary conditions taking into account the surface roughness in metallic or dielectric films has been discussed. Our…
Enhancing the absorption and emission of electromagnetic waves over a broad range of wavelengths is a topic of fundamental and applied interest in photonics and energy research. In the context of light trapping in solar cells, for example,…
The cross section of light absorption by semiconductor quantum dots in the case of the resonance with excitons $\Gamma_6 \times \Gamma_7$ in cubical crystals $T_d$ is calculated. It is shown that an interference of stimulating and induced…
The photomolecular effect has been hypothesized to enhance evaporation of water at visible wavelengths. This study develops a measurement technique to investigate its presence and magnitude at the liquid-vapor interface of water. The…
The multiple passages of light through an absorption inhomogeneity of finite size deep within a turbid medium is analyzed for optical imaging using the ``self-energy'' diagram. The nonlinear correction becomes more important for an…
Nonlinear hopping absorption of ultrasound and electromagnetic waves in amorphous and doped semiconductors is considered. It is shown that even at low amplitudes of the electric (or acoustic) field the nonlinear corrections to the…
Emission and absorption of light lie at the heart of light-matter interaction. Although emission and absorption rates are regarded as intrinsic properties of atoms and molecules, various ways to modify these rates have been sought in…
$\beta$-Ga$_2$O$_3$ is an ultra-wide bandgap semiconductor and is thus expected to be optically transparent to light of sub-bandgap wavelengths well into the ultraviolet. Contrary to this expectation, it is found here that free electrons in…
Broad bandwidth, infrared light sources have the potential to revolutionize inertial confinement fusion (ICF) by suppressing laser-plasma instabilities. There is, however, a tradeoff: The broad bandwidth precludes high efficiency conversion…
The optical absorption of a single spherical semiconductor quantum dot in an electrical field is studied taking into account the nonlocal coupling between the field of the light and the polarizability of the semiconductor. These nonlocal…
Intermediate band solar cells (IBSCs) pursue the increase in efficiency by absorbing below-bandgap energy photons while preserving the output voltage. Experimental IBSCs based on quantum dots have already demonstrated that both…
The resonant absorption of light by an ensemble of absorbers decreases when the resonance is inhomogeneously broadened, as only a fraction of the ensemble contributes to the absorption at any given optical frequency. Recovering the lost…
We theoretically study nonlinear optics of excitons under intense THz irradiation. In particular, the linear near infrared absorption and resonantly enhanced nonlinear sideband generation are described. We predict a rich structure in the…
We have theoretically investigated nonlinear free-carrier absorption of terahertz radiation in InAs/AlSb heterojunctions. By considering multiple photon process and conduction-valence interband impact ionization (II), we have determined the…