QUANTUM-THEORY OF ELECTROMAGNETICALLY INDUCED SUPPRESSION OF ABSORPTION AND INVERSIONLESS LASING IN A 3-LEVEL SYSTEM

Abstract

A full quantum treatment is given of suppression of absorption and lasing without inversion in a Lambda-type three-level atom induced by a strong driving field resonant with the two lower levels. The nature of the quantum interference leading to the suppression of absorption and lasing without inversion and its relation to the initial state preparation are studied. Particular attention is given to the effects that arise specifically from the quantum nature of the driving field. It is shown that, because of the distinguishability of the states of the driving field that have different photon numbers, destructive interference is confined to occur within a finite region of the photon number space. A complete cancellation of absorption predicted in the semiclassical theory should thus be regarded as resulting from an ideal behavior achieved only in the classical limit when the driving field is given as a strong coherent field.