DC-FIELD-COUPLED AUTOIONIZING STATES FOR LASER ACTION WITHOUT POPULATION-INVERSION

We consider how externally coupled (e.g., dc-field-coupled) autoionizing states can be useful in producing gain without population inversion. The dc fields produce new absorption minima that enable one to obtain laser action in different frequency regions depending on the strength of the coupling. We calculate absorption and emission profiles assuming that one of the autoionizing states is incoherently pumped as in most conventional laser models. We present numerical results that demonstrate gain regions without population inversion. © 1990 The American Physical Society.