Peng Jin-Sheng

Emission spectrum of a Λ-type three-level atom driven by the squeezed coherent field and grey-body radiation field

Abstract By means of quantum electrodynamics, an analytical expression of emission spectrum for a Λ-type three-level atom with the two non-degenerate lower levels in the cavity is given. The character of the emission spectrum for the input in pure number state, a squeezed coherent state and grey-body state are exhibited. The effects of the atomic initial state, the field property, the cavity absorptivity and the system temperature on the time-dependent physical spectrum are analysed.

Population Inversion of a V-type Three-Level Atom due to the Effect of Cavity-Induced Quantum Interference

A cavity-modified master equation is derived for a coherently driven V-type three-level atom coupled to a single-mode cavity in the bad cavity limit. The influences of the cavity-induced quantum interference on the steady-state populations are analysed. We show that the population inversion can occur due to the effect of cavity-induced quantum interference. PACS: 42. 50. Dv, 42. 50. Gy

Squeezing of Field in the System of a Kerr Medium Embedded in a Nondegenerate Two-Photon Absorption Cavity

Squeezing properties of field in the system of a Kerr medium embedded in a non-degenerate two-photon absorption cavity interacting with a two-mode uncorrelated coherent field are discussed. We find that both the two-mode squeezing and the sum squeezing of field can arise and can be enhanced due to the Kerr effect.

Absorption Spectrum of a Driven Two-Level Atom in a Tunable Cavity with Injected Squeezed Vacuum

The absorption spectrum of a driven two-level atom in a frequency tunable cavity with injected squeezed vacuum is investigated. The line shape of the spectra depends on the relative phase between the driving field and the squeezed vacuum, and the frequency detuning between the driving field and the cavity mode. Line narrowing and probe gain can occur and be enhanced by adjusting the phase and detuning.

Squeezed Cascade Two-Quantum-Beat Lasers

Noise squeezing of intensity difference between the pair of sum modes may be generated in a cascade laser of ? and V quantum-beats. The best achievable squeezing is up to 50% below the shot noise limit. This new kind of squeezed lasers has potential for quantum communications and precision measurements.

Coherent population trapping in multilevel laser-induced continuum structure system including cascade two-photon processes

We have investigated the atomic coherent population trapping in a multilevel laser-induced continuum structure system including cascade two-photon processes, in which two sets of quasicontinua of excited levels to be modeled as the Bixon-Jortner quasicontinuum are laser-embedded into a previously structureless atomic continuum. The condition leading to the atomic coherent population trapping and the coherent population trapping state are given explicitly. And the effects of the Fano factors, the laser intensities and the detunings on the amount of population trapped in the atomic bound states and the populations distributed in the two sets of quasicontinua are also examined.

New treatment of quantum revivals

When a real system consisting of a two-level atom and a single-mode field is described by a pair of state vectors, the energy of the atom shows a stationary cosine oscillation. When this energy is averaged over an ensemble, we get the usual periodic decays and revivals of the mean value of the energy.

Nonlocality Property of Three-Mode Correlated Fields

Four three-mode correlated states are generated by two beam splitters. We show that, by means of parity measurement, those light fields exhibit the nonlocality represented by the violation of the Bell inequality. The conditions of the maximum violation are also studied.

Photoionization properties of an atom with two autoionizing states

We have investigated the photoionization properties of an atom with a ladder coupling scheme involving two autoionizing states coupled to each other. The effects of the coherent coupling between two autoionizing states and between the low-lying autoionizing state and the continuum on the ionization yield are discussed. The conditions leading to atomic coherent population trapping and the coherent population trapping states are given explicitly.

A study on composite scattering of targets and environment

An analysis of the composite scattering between the target and the environment is made. The two-dimensionally fractal function is used to model the rough surface, and the scattered electromagnetic field is calculated by using Kirchhoffs approximation. The validity of the result is assured by some reference, which indicates that the methods in this paper are reliable, then a simple and practical example is given.