Inversionless gain enhancing due to Doppler broadening in a closed lambda-type system
Ma Hui(马慧)a), Tian Shu-Fen(田淑芬)b), Tan Xia(谭霞)a), Tong Dian-Min(仝殿民)a), and Fan Xi-Jun(樊锡君)a)†
a College of Physics and Electronics, Shandong Normal University, Jinan 250014, China; b Communication College, Shandong Normal University, Jinan 250014, China
Abstract 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)).
Received: 24 December 2006
Revised: 17 April 2007
Accepted manuscript online:
(Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption)
Fund: 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 Opt
Cite this article:
Ma Hui(马慧), Tian Shu-Fen(田淑芬), Tan Xia(谭霞), Tong Dian-Min(仝殿民), and Fan Xi-Jun(樊锡君) Inversionless gain enhancing due to Doppler broadening in a closed lambda-type system 2007 Chinese Physics 16 2973
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