中国物理B ›› 2009, Vol. 18 ›› Issue (12): 5342-5349.doi: 10.1088/1674-1056/18/12/037
樊锡君1, 刘中波1, 马慧2, 仝殿民3
Fan Xi-Jun(樊锡君)a)†, Ma Hui(马慧)b), Liu Zhong-Bo(刘中波)a), and Tong Dian-Min(仝殿民)c)
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 Λ-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.
中图分类号: (Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption)