相关论文: Lossless anomalous dispersion and an inversionless…
Interest in lossless nonlinearities has focussed on the the dispersive properties of $\Lambda $ systems under conditions of electromagnetically induced transparency (EIT). We generalize the lambda system by introducing further degenerate…
The mechanisms leading to a seemingly superluminal propagation of light in dispersive media are examined. The anomalous dispersion near an absorption line, involved in the first experiments displaying negative group velocity propagation, is…
Anomalous dispersion cannot occur in a transparent passive medium where electromagnetic radiation is being absorbed at all frequencies, as pointed out by Landau and Lifshitz. Here we show, both theoretically and experimentally, that…
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…
The concept of random walk, in which particles or waves undergo multiple collisions with the microscopic constituents of a surrounding medium, is central to understanding diffusive transport across many research areas. However, this…
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…
Light induced absorption with population inversion and amplification without population inversion (LWI) in a coherently prepared closed three level V - type system are investigated. This study is performed from the point of view of a two…
We offer a general treatment of electromagnetically induced transparency (EIT) in a five level system consisting of four metastable ground states. Two additional RF/microwave fields coherently couple the two ground states of the standard…
Defect detection is the task of identifying defects in production samples. Usually, defect detection classifiers are trained on ground-truth data formed by normal samples (negative data) and samples with defects (positive data), where the…
Dissipation is a ubiquitous phenomenon in dynamical systems encountered in nature because no finite system is fully isolated from its environment. In optical systems, a key challenge facing any technological application has traditionally…
We propose a method to achieve amplification without population inversion by anisotropic molecules whose orientation by an external electric field is state-dependent. It is based on decoupling of the lower-state molecules from the resonant…
We investigate the behavior of fast light pulse propagation in an N-type Doppler-broadened 4-level atomic system using double Raman gain processes. This system displays novel and interesting results of two controllable pairs of the double…
From the spread of pollutants in the atmosphere to the transmission of nutrients across cell membranes, anomalous diffusion processes are ubiquitous in natural systems. The ability to understand and control the mechanisms guiding such…
A method to interpret probe spectra of driven degenerate atomic systems is discussed. The dressed-atom multiphoton spectroscopy (DAMS) is based on a dressing of the atomic system with the strong coupling field, followed by a perturbative…
We present a peculiar transition triggered by infinitesimal dissipation in the interpolating Dicke-Tavis-Cummings model. The model describes a ubiquitous light-matter setting using a collection of two-level systems interacting with quantum…
We investigate the dispersion and the absorption properties of a weak probe field in a three-level Lambda-type atomic system. We use just an incoherent field for controlling the group velocity of light. It is shown that the slope of…
We consider propagation of a probe pulse in an atomic medium characterized by a combined tripod and Lambda ($\Lambda$) atom-light coupling scheme. The scheme involves three atomic ground states coupled to two excited states by five light…
We present a five level atomic system in which the index of refraction of a probe laser can be enhanced or reduced below unity with vanishing absorption in the region between pairs of absorption and gain lines formed by dressing of the…
Previously, we had proposed an optically-pumped five-level Gain EIT (GEIT) system, which has a transparency dip superimposed on a gain profile and exhibits a negative dispersion suitable for the white-light-cavity signal-recycling (WLC-SR)…
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…