Vol. 46, Issue 1, pp. 93-102 (2016)

Abstract

In our previous paper (Doan Quoc K. et al., Physica Scripta T147, 2012, article 014008), electromagnetically induced transparency for Λ-like systems consisting of two lower bound states and a flat continuum coupled to an autoionization state embedded in it has been considered, in which the laser coupling light is modeled by white noise. In this paper, we investigate a similar scheme, where the continuum involved in the problem is replaced by one with so-called the double-Λ system, when instead of one autoionization state we have two autoionization states of the same energy embedded in the continuum. For such a system containing degenerate autoionization levels we derive a set of coupled stochastic integro-differential equations which can be averaged exactly. This leads to the exact formula determining the stationary solution for the electric susceptibility. Dispersion and absorption spectra for electromagnetically induced transparency are found and compared with those obtained previously by us and other authors.