建立微波驱动基态精细结构跃迁的Λ型三能级系统, 研究基于自发辐射相干控制的电磁感应透明诱导无反转光放大效应.微波场作用于基态精细结构能级之间, 产生3个透明窗口, 利用适当角度的自发辐射相干效应与电磁感应透明耦合, 实现透明向光放大的转化.结果表明, 透明转化为光放大时, 激发态与基态能级之间以及两个基态能级之间均不出现粒子数反转, 但在产生光放大的过程中必须经历两个基态能级出现粒子数反转的状态.调节微波场的频率失谐量可以改变基态能级上的粒子数分布, 有利于无反转光放大的产生.

The transformation from electromagnetically induced transparency to amplification without inversion based on spontaneously generated coherence was studied by proposing a lambda type three-level system. Three transparency windows are observed when two ground state hyperfine levels are driven by a microwave field. The transparency shifts into amplification by using the coupling of electromagnetically induced transparency and spontaneously generated coherence with appropriate angle. The results show that there is no population inversion between the ground state and the excited state level and no population inversion between two ground state hyperfine levels when amplification is observed, but the system must go through population inversion of two ground state levels in the process of generating amplification. The populations of two ground state levels can be controlled though the adjustment of the frequency detuning of the microwave field to facilitate the generation of amplification.