Experimental and theoretical features of strong suppression and shifting phenomena in odd-photon resonant excitations and stimulated emissions

摘要

Discriptions are given of recent theoretical and experimental results of dramatic effects, during the interval of the excitation pulse, in optically pumped stimulated emissions (OPSE). Forward-directed OPSE from a two-photon resonantly excited state to a lower state which is also coupled to the ground state is strongly suppressed and backward emissions are frequency shifted. Surprisingly, the effects are caused by an interference from a wave-mixing field. Several other implications of this effect are given and, on the basis of this phenomenon, several puzzling ASE observations mentioned in other published work are noted and clarified.