Inversionless gain enhancing due to Doppler broadening in a closed lambda-type system  

作　　者：马慧 田淑芬 谭霞 仝殿民 樊锡君 

机构地区：[1]College of Physics and Electronics, Shandong Normal University, Jinan 250014, China [2]Communication College, Shandong Normal University, Jinan 250014, China

出　　处：《Chinese Physics B》2007年第10期2973-2979,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China （Grant No 10675076）, the Natural Science Foundation of Shandong Province of China （Grant No Y2006A21） and the State Key Laboratory of High Field Laser Physics, Shanghai Institute of 0ptics and Fine Mechanics, Chinese Academy of Sciences.

摘　　要：An analysis is made of the effect of Doppler broadening on gain without inversion （GWI） from different aspects in a closed lambda-type three-level system with an incoherent pump. It is shown that, regardless of the driving field being on resonance or not, for the counter- or co-propagating of the probe and driving fields （PDF）, GWI does not monotonically decrease or increase with increasing Doppler width. Except for the case of counter-propagating PDF with off-resonance driving field, at a suitable Doppler width one can obtain a gain maximum value much larger than that without Doppler broadening; especially in the situation of the resonant driving field, the co-propagating geometry leads to a larger GWI. In addition, for the counter-propagating geometry, when Doppler width is larger enough, GWI oscillation occurs, and the oscillation amplitude and region increase with increasing Doppler width. These conclusions are very different from that obtained in previous investigation （Lukin et al, Laser Phys. 6 436 （1996））.

关 键 词：closed system Doppler broadening gain without inversion 

分 类 号：O56[理学—原子与分子物理]