Comparison between effects of Doppler broadening on pure and non-pure inversionless gain with frequency up-conversion  

作　　者：樊锡君 马慧 刘中波 仝殿民 

机构地区：[1]College of Physics and Electronics,Shandong Normal University [2]School of Mathematics and Physics,Shandong Institute of Light Industry [3]School of Physics and Microelectronics,Shandong University

出　　处：《Chinese Physics B》2009年第12期5342-5349,共8页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Shandong Province,China (Grant No Y2006A21);the National Natural Science Foundation of China (Grant No 10675076)

摘　　要：A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one-photon inversion does not occur but two-photon inversion is present, in a closed A-type three-level system with incoherent pumping. It is shown that when the driving field is resonant but the probe field is not, in a certain range of Doppler width, for the case of the lower degree of frequency up-conversion, generally, pure gain without inversion increases monotonically and non-pure gain without inversion does not monotonically increase or decrease with increasing Doppler width; for the case of the higher degree of frequency up-conversion, pure gain without inversion decreases monotonically but non-pure gain without inversion cannot be produced. In the case of two-photon resonance, in some range of Doppler width, pure gain without inversion does not monotonically increase or decrease while non-pure gain without inversion decreases monotonically with Doppler width increasing. Finally, an experimental scheme for examining our theoretical result is given.A study is made of the effects of Doppler broadening on pure gain without inversion, which means that neither one-photon nor two-photon inversions are allowed, and non-pure gain without inversion, which means that one-photon inversion does not occur but two-photon inversion is present, in a closed A-type three-level system with incoherent pumping. It is shown that when the driving field is resonant but the probe field is not, in a certain range of Doppler width, for the case of the lower degree of frequency up-conversion, generally, pure gain without inversion increases monotonically and non-pure gain without inversion does not monotonically increase or decrease with increasing Doppler width; for the case of the higher degree of frequency up-conversion, pure gain without inversion decreases monotonically but non-pure gain without inversion cannot be produced. In the case of two-photon resonance, in some range of Doppler width, pure gain without inversion does not monotonically increase or decrease while non-pure gain without inversion decreases monotonically with Doppler width increasing. Finally, an experimental scheme for examining our theoretical result is given.

关 键 词：A-type three-level system Doppler broadening gain without inversion frequency upconversion 

分 类 号：O437.1[机械工程—光学工程]