标题：Phase-dependent gain without inversion in an inhomogeneous broadened quasi Lambda-type four-level system with VIC
作者：Liu, Zhongbo; Wang, Zhendong; Jia, Kening; Tong, Dianmin; Fan, Xijun
作者机构：[Liu, Zhongbo; Wang, Zhendong; Jia, Kening; Fan, Xijun] Shandong Normal Univ, Coll Phys & Elect, Jinan 250014, Peoples R China.; [Tong, Dianmin] Sha 更多
会议名称：Conference on Quantum and Nonlinear Optics
会议日期：OCT 18-19, 2010
来源：QUANTUM AND NONLINEAR OPTICS
关键词：quasi Lambda-type four-level system; relative phase; Doppler broadening;; vacuum induced coherence; lasing without inversion; gain
摘要：The effect of the relative phase (phi) between the probe and driving fields on the gain without inversion (GWI) is studied in a Doppler broadened quasi Lambda-type four-level atomic system with vacuum induced coherence (VIC). It is shown that: The probe detuning region in which GWI exists and size of GWI are very sensitive to variation of the relative phase, the Doppler width (D) also has dramatically modulation role on the phase-dependent GWI. The GWI maximum value (G(max)) varies periodically with the relative phase varying, the period is 2 pi; but the concrete varying rule is closely related to the value of the Doppler width. In the case of D = 0 (i.e. without Doppler broadening), when 0 < phi < pi, G(max) increases monotonously with f increasing; when pi < phi < 2 pi, G(max) decreases monotonously with f increasing; when phi = pi, G(max) has the largest value. Under the condition of D not equal 0 (i.e. Doppler broadening presents), in both regions 0 < phi < pi and pi < phi < 2 pi, G(max) does not monotonically increase or decrease with phi increasing; the value of phi, which corresponds to the largest value of G(max), decreases gradually from pi with D increasing, when value of D is large enough, the value of phi, which corresponds to the largest value of G(max), is about pi/2. In general speaking, G(max) decreases with D increasing; but G(max) larger than that in the corresponding static atomic system (D = 0) can be gotten by choosing suitable values of phi and D.