Eur. Phys. J. D 23, 315-319 (2003)
https://doi.org/10.1140/epjd/e2003-00052-6

Phase and amplitude control of the inversionless gain in a microwave-driven Λ-type atomic system

¹ College of Physics, Jilin University, Changchun 130023, P.R. China
² China Center of Advanced Science and Technology (World Laboratory), P.O. Box 8370, Beijing 100080, P.R. China

Corresponding author: ^a jygao@mail.jlu.edu.cn

Received: 20 June 2002
Revised: 5 December 2002
Published online: 4 March 2003

Abstract

In order to achieve the phase-sensitive probe gain without population inversion, we investigate a three-level Λ-type atomic system driven by a coherent field and a microwave field. It is shown that, by modulating the relative phase of applied fields, we can obtain quite high inversionless gain at different probe detunings and change the gain behavior of the probe correspondingly. We find that amplitudes of the coherent field and the microwave field are also important factors that can result in different gain behavior of the probe. Here, we use the microwave field to induce the quantum coherence between the two ground levels, which is necessary for phase-sensitive effects, since it can result in the interference between two different transition channels.