Quenching of spontaneous emission via quantum interference

Abstract
A four-level atom, driven by a coherent field, is considered. We show that under certain conditions complete quenching of spontaneous emission is possible. Hence the population inversion on some specific atomic transitions can be created using a very weak incoherent pumping. We investigate the physics of the effect using bare and dressed states. The proposed scheme may be useful, in principle, for generation of high-frequency and/or high power laser light. DOI: http://dx.doi.org/10.1103/PhysRevA.55.4454 © 1997 The American Physical Society