Related papers: Lasing oscillation condition and group delay contr…
The first arriving signal (FAS) in a layered waveguide is investigated. It is well known that the velocity of such a signal is close to the velocity of the fastest medium in the waveguide, and it may be bigger than the fastest group…
We demonstrate theoretically that electromagnetically induced transparency can be achieved in metamaterials, in which electromagnetic radiation is interacting resonantly with mesoscopic oscillators rather than with atoms. We describe novel…
We show that electromagnetically-induced transparency and lasing without inversion are simultaneously achieved for microwave fields by using a fluxonium superconducting circuit. As a result of the $\Delta$ energy-level structure of this…
Following up on previous studies on parity-time-symmetric gain-loss bi-layers, and inspired by formal analogies with plasmonic waveguides, we study non-Hermiticity-induced wave confinement and guiding phenomena that can occur in…
We theoretically study the transmission of a weak probe field under the influence of a strong pump field in a coupled nanomechanical resonator-superconducting microwave cavity system. Using the standard input-output theory, we find that…
We present a discrete model of resonant scattering of waves by an open periodic waveguide. The model elucidates a phenomenon common in electromagnetics, in which the interaction of plane waves with embedded guided modes of the waveguide…
Using the transfer-matrix approach and solving time-domain differential equations, we analyze the loss compensation mechanism in multilayer systems composed of an absorbing transparent conductive oxide and dielectric doped with an active…
We report on lasing at visible wavelengths in arrays of ferromagnetic Ni nanodisks overlaid with an organic gain medium. We demonstrate that by placing an organic gain material within the mode volume of the plasmonic nanoparticles both the…
We show that optical tachyonic dispersion corresponding to superluminal (faster than-light) group velocities characterizes parametrically amplifying media. The turn-on of parametric amplification in finite media, followed by illumination by…
We study the differential group delay that can be obtained in coupled micro-ring resonator waveguides with longitudinal offset couplers. Various devices based on this effect are proposed and analyzed using a finite-differences time-domain…
We revisit the calculation of the medium-induced gluon radiative spectrum and propose a novel expansion scheme that encompasses the two known analytic limits: i) the high frequency regime dominated by a single hard scattering that…
Radio signals are delayed when propagating through plasma. This type of delay is frequency-dependent and is usually used for estimating the projected number density of electrons along the line of sight, called the dispersion measure. The…
Plasmonic nanoantenna is of promising applications in optical sensing, single-molecular detection, and enhancement of optical nonlinear effect, surface optical spectroscopy, photochemistry, photoemission, photovoltaics, etc. Here we show…
Light propagating in an optical waveguide can gain or lose power through interaction with a travelling acoustic wave or radio-frequency modulation of permittivity. Here, we model this propagation by considering an optical wave interacting…
We theoretically propose directional, low-threshold plasmon lasing in both the near-infrared and visible wavelengths by utilizing spatially coherent surface plasmon polaritons on a meta-surface. The gain strength required for threshold…
Steady-state plasmonic lasing is studied theoretically for a system consisting of many dye molecules arranged regularly around a gold nano-sphere. A three-level model with realistic molecular dissipation is employed to analyze the…
We investigate the transient response of a $\Lambda$-type system with one transition decaying to a modified radiation reservoir with an inverse square-root singular density of modes at threshold, under conditions of transparency. We…
We report the observation of large ($\sim 40%$) laser-induced above-bandgap transparency in GaAs at room temperature. The induced transparency is present only during the pulse width of the driving midinfrard laser pulses and its spectral…
We report on room temperature phonon-assisted whispering gallery mode (WGM) lasing in ZnO microwires. For WGM laser action on the basis of the low gain phonon scattering process high quality resonators with sharp corners and smooth facets…
Absorption induced transparency is an optical phenomenon that occurs in metallic arrays of nanoholes when materials featuring narrow lines in their absorption spectra are deposited on top of it. First reported in the visible range, using…