Related papers: Albedo and laser threshold of a diffusive Raman ga…
A theory is presented (and supported by numerical simulations) for phase-coherent reflection of light by a disordered medium which either absorbs or amplifies radiation. The distribution of reflection eigenvalues is shown to be the Laguerre…
We address the problem of achieving a random laser with a cloud of cold atoms, in which gain and scattering are provided by the same atoms. In this system, the elastic scattering cross-section is related to the complex atomic…
The previous research proves that the random laser emission reflects not only the scattering properties but also the absorption properties. The random laser is therefore considered a potential tool for optical properties sensing. Although…
This study examines the Raman scattering and charge transfer properties of molecules adsorbed on the surface of a tetrahedral Au$_{120}$ nanoparticle based on the time-dependent density functional tight-binding (TD-DFTB) method. We study…
The range of stimulated Raman scattering (SRS) frequencies covers a domain which at the low end abuts half the laser frequency, omega_0 / 2, according to the simplest SRS theories, corresponding to scatter from electron densities near 1/4…
The peculiar characteristics of random laser emission have been studied in many different media, leading to a classification of the working regimes based on the statistics of spectral fluctuations. Alongside such studies, the possibility to…
When a monochromatic electromagnetic plane-wave arrives at the flat interface between its transparent host (i.e., the incidence medium) and an amplifying (or gainy) second medium, the incident beam splits into a reflected wave and a…
When a monochromatic electromagnetic plane-wave arrives at the flat interface between its transparent host (i.e., the incidence medium) and an amplifying (or gainy) second medium, the incident beam splits into a reflected wave and a…
We perform high resolution spectroscopy of $N_2^+$ emission in light filaments using a controlled pump at 795 followed by a second harmonic weak probe. Our result suggests that transient gain is achieved by resonant stimulated Raman…
From the earth's crust to the human brain, remitted waves are used for sensing and imaging in a diverse range of diffusive media. Separating the source and detector increases the penetration depth of remitted light, yet rapidly decreases…
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…
We address the problem of achieving an optical random laser with a cloud of cold atoms, in which gain and scattering are provided by the same atoms. The lasing threshold can be defined using the on-resonance optical thickness b0 as a single…
Transmission of light through an atomic sample placed between crossed polarizers in a magnetic field is jointly determined by Faraday rotation and net absorption: transmission increases with rotation and decreases with absorption. Both…
The work was aimed to generate random laser emissions simultaneously at two wavelengths in a weakly scattering system containing mixture of binary dyes, rhodamine-B (Rh-B) and oxazine-170 (O-170) dispersed with ZnO nano-particles served as…
Propagation of light in a highly scattering medium is among the most fascinating optical effect that everyone experiences on an everyday basis and possesses a number of fundamental problems which have yet to be solved. Conventional wisdom…
While the mathematical foundations of score-based generative models are increasingly well understood for unconstrained Euclidean spaces, many practical applications involve data restricted to bounded domains. This paper provides a…
Conventional lasers make use of optical cavities to provide feedback to gain media. Conversely, mirrorless lasers can be built by using disordered structures to induce multiple scattering, which increases the effective path length in the…
We report the analysis of measurements of the complex magnetic permeability ($\mu_r$) and dielectric permittivity ($\epsilon_r$) spectra of a rubber radar absorbing material (RAM) with various MnZn ferrite volume fractions. The…
Transmission eigenchannels and associated eigenvalues, that give a full account of wave propagation in random media, have recently emerged as a major theme in theoretical and applied optics. Here we demonstrate, both analytically and…
We study laser generation in 1D distributed feedback lasers with amplifying and lossy layers. We show that when the lasing frequency differs from the transition frequencies of the amplifying medium, loss induced lasing may occur due to the…