Gain leveling using electromagnetically induced transparency

LiYong-Fang, SunJian-Feng

M. Artoni

Seyed M. Sadeghi, Jochen Meyer

We study the generation of an ultranarrow gain spectrum in an atomic transition when the upper transition level is coupled to the lower transition level by one laser and to a metastable state by another laser. It is shown that this spectrum switches abruptly into an ultranarrow absorption line with an increase in the first laser intensity. These results are explained by investigating the electromagnetically induced transparency (EIT) in a system where the upper transition level is coupled to two metastable states by two laser fields (K system). We discuss various features of such a transparency and show how it can be described as a structuring process, similar to the laser-induced continuum structure. Utilizing such a description of EIT, we explain the ultranarrow gain generation as a stimulated Rayleigh scattering process.

Li Yongfang, Sun Jian-feng, 陕西师范大学物理学与信息技术学院,西安〓710062

In this paper, we study the effects of Rabi frequencies and multi-path radiation on the electromagnetically induced transparency (EIT) and the inversionless gain in a ladder- four-level system driven by two-coherent fields- The Rabi frequencies of the field-driven transition from the upper level to middle levels play an important role for the realization of the ultra-narrow EIT and inversionless gain- Different excitation mechanism can change the position of the EIT- The action of the spontaneous alignment of the dipole moment is investigated- The explanation for the numerical results is presented using the theory of dressed state

Stephen E. Harris, G. Y. Yin, A. Kasapi +2 more

John A. Vaccaro, Alan V. Durrant, Derek Richards +3 more

A rigorous diagrammatic description of stochastic wavefunction evolution for electromagnetically induced transparency (EIT) and inversionless gain in coherently driven three-level systems is developed and applied to transient and steady-state conditions. Wavefunction trajectories are illustrated for cases that include A and V-type EIT, shelving and dressed-state resonances.