Related papers: Group velocity control in a four level system thro…
We consider an optomechanical double-ended cavity under the action of a coupling laser and a probe laser in electromagnetically induced transparency configuration. It is shown how the group delay and advance of the probe field can be…
We investigate nonlinear Kerr-induced coherence effect on a superluminal probing light pulse in a gain-assisted N-type 4-level atomic system via an intense monochromatic laser field. The dispersion exhibits a novel, interesting and useful…
We study the manipulation of slow light with an orbital angular momentum propagating in a cloud of cold atoms. Atoms are affected by four copropagating control laser beams in a double tripod configuration of the atomic energy levels…
In the recent experiment, the phenomena of superluminal and slow-light propagation in dispersive medium were found, and there are various explanation in theory. We find the phenomenon can be explained by multiple-photon interaction.…
We have demonstrated that near complete coherence can be achieved in a four level double lambda-like systems using a train of ultra-short optical pulses. The effect of the Doppler broadening has been analyzed and a scheme has been proposed…
Refractive index and absorption experienced by a probe field propagating through a three-level atomic medium can be effectively manipulated by the bistable behavior of a control field. The probe field couples the lower transition of the…
The propagation of light-pulse with negative group-velocity in a nonlinear medium is studied theoretically. We show that the necessary conditions for these effects to be observable are realized in a three-level $\Lambda$-system interacting…
We study a new mechanism to discover dark photon fields, by resonantly triggering two photon transitions in cold gas preparations. Using coherently prepared cold parahydrogen, coupling sensitivity for sub-meV mass dark photon fields can be…
We have observed the spatial interactions between two ultra-weak optical beams that are initially collinear and non-overlapping. The weak beams are steered towards each other by a spatially varying cross-Kerr refractive index waveguide…
The resonance fluorescence of a four-level atom in J = 1/2 to J = 1/2 transition driven by two coherent fields is studied. We find that the incoherent fluorescence spectrum shows a direct indication of vacuum-induced coherence in the atomic…
When two-photon interactions are induced by down-converted light with a bandwidth that exceeds the pump bandwidth, they can obtain a behavior that is pulse-like temporally, yet spectrally narrow. At low photon fluxes this behavior reflects…
We present a microscopic explanation of the controversially discussed transient negative differential transmission observed in degenerate optical pump-probe measurements in graphene. Our approach is based on the density matrix formalism…
We propose a method to controllably suppress the effect of the four-wave mixing caused by the coupling of the strong control optical field to both optical transitions in the $\Lambda$ system under the conditions of electromagnetically…
The unusually narrow features in the fluorescence from Rubidium-85 driven by cooling and repumper laser fields, reported in an earlier experiment [1] are explained on the basis of a four-level density matrix calculation. Quantum effects…
Nonadiabatic change of the control field or of the low-frequency coherence allows for an almost instantaneous change of the signal field propagating in a thick resonant absorber where electromagnetically induced transparency is realized.…
In this article, we study the optical response of a duplicated two-level atomic medium subjected to a stationary control field and a weak co-propagating probe field, orthogonally polarized to each other. We show that both the reflected and…
We report the experimental demonstration of the superluminal propagation of multi-spatial-mode images via four-wave mixing in hot atomic vapor, in which all spatial sub-regions propagate with negative group velocities. We investigate the…
We study the propagation of a quantum probe light in an ensemble of "3+1"-level atoms when the atoms are coupled to two other classical control fields. First we calculate the dispersion properties, such as susceptibility and group velocity,…
An absorption of a weak pulse by two identical atoms moving in a trap is investigated. Based on atom-light interactions we present a microscopic model of a two-body wave function diagnosis. We study the influence of pulse properties on the…
The reflection spectrum of a probe light in a -type three-level atomic system coupled by an off-resonant standing-wave is investigated experimentally and theoretically. We show that the maximum value of reflection coefficient occurs when…