相关论文: First-Principles Threshold Calculation of Photonic…
A new type of the THz laser is proposed. A coherent tera-hertz light is emitted through the backward Raman scattering between a visible light laser and a relativistic electron beam. The threshold conditions for the laser intensity and the…
An extended version of the R-matrix methodology is presented for calculation of radiative parameters for improved plasma opacities. Contrast and comparisons with existing methods primarily relying on the Distorted Wave (DW) approximation…
In the last two decades, Fresnel diffraction (FD) of a plane wave from phase steps has been systematically studied and applied for precise measurements of light wavelength, and height and refractive index of the step. In this study we…
Laser-electron beam collisions that aim to generate electron-positron pairs require laser intensities $I \gtrsim 10^{21} ~\textrm{W/cm}^2$, which can be obtained by focusing a 1-PW optical laser to a spot smaller than 10 $~\mu$m. Spatial…
Raman spectroscopy is an advantageous method for studying the local structure of materials, but the interpretation of measured spectra is complicated by the presence of oblique phonons in polycrystals of polar materials. Whilst group theory…
The new single-channel, single-energy partial wave analysis method based on a simultaneous use of amplitude and partial wave analysis called AA/PWA, developed and tested on $\eta$ photoproduction in ref. Svarc et al, PRC 102, 064609 (2020),…
Four-wave mixing can be used to generate coherent output beams, with frequencies difficult to acquire in commercial lasers. Here a single narrow ECDL locked to the two photon 5s-5d transition in rubidium is combined with a tapered amplifier…
We investigate lasing thresholds in a representative photonic molecule composed of two coupled active cylinders of slightly different radii. Specifically, we use the recently formulated steady-state ab initio laser theory (SALT) to assess…
The threshold properties of photonic crystal quantum dot lasers operating in the slow-light regime are investigated experimentally and theoretically. Measurements show that, in contrast to conventional lasers, the threshold gain attains a…
The interaction of laser pulses with thin grating targets, having a periodic groove at the irradiated surface, has been experimentally investigated. Ultrahigh contrast ($\sim 10^{12}$) pulses allowed to demonstrate an enhanced laser-target…
Devising a computational tool that assesses the thermodynamic stability of materials is among the most important steps required to build a ``virtual laboratory'', where materials could be designed from first-principles without relying on…
The measurement of peak laser intensities exceeding $10^{20} \text{W/cm$^2$}$ is in general a very challenging task. We suggest a simple method to accurately measure such high intensities up to about $10^{23} \text{W/cm$^2$}$, by colliding…
The application of wavelet transforms to Synthetic Aperture Radar (SAR) imagery has improved despeckling performance. To deduce the problem of filtering the multiplicative noise to the case of an additive noise, the wavelet decomposition is…
A system of automated computerized Langmuir probe measurements is used in order to determine the plasma parameters in a plasma reactor constructed for cleaning of metallic artifacts by RF discharge. A compensated probe insures the…
We develop a first-principles scheme based on the continued fraction approach an d ultrasoft pseudopotentials to calculate K-edge X-ray absorption spectra in solids. The method allows for calculations of K-edge X-ray absorption spectra in…
We consider the problem of synthetic aperture radar (SAR) imaging and motion estimation of complex scenes. By complex we mean scenes with multiple targets, stationary and in motion. We use the usual setup with one moving antenna emitting…
We derive expressions for the coupling coefficients for electromagnetic four-wave mixing in the non-linear quantum vacuum. An experimental setup for detection of elastic photon-photon scattering is suggested, where three incoming laser…
Today's high-power laser systems are capable of reaching photon intensities up to $10^{22}$ W/cm^2, generating plasmas when interacting with material. The high intensity and ultrashort laser pulse duration (fs) make direct observation of…
We investigate the interaction between an optical laser and an ionic crystal and reveal coherent emission of axions through phase-match between laser and axion fields. Such emission is further enhanced by stacking thin crystal layers of…
Heterogenous reactions typically consist of multiple elementary steps and their rate coefficients are of fundamental importance in elucidating the mechanisms and micro-kinetics of these processes. Transition-state theory (TST) for…