【摘要】 利用开放的V型系统密度矩阵运动方程组和Hurwitz判据研究了光场的横向效应。结果表明:与平面波近似情况相比,光场的横向分布将使系统通过无激光解失稳而导致无反转激光(LWI)的方式发生明显的改变,并使系统更容易通过pitchfork分岔失稳而获得LWI;激活介质横向尺寸与光束束腰的比值对能够产生LWI的失稳区的大小具有决定性的影响,而且Raman反转区随这个比值增大而增大;非饱和增益、腔损耗、原子注入速率比以及退出速率的变化对于能够产生LWI的失稳区的影响与平面波情况是大不相同的。更多还原

【Abstract】 The transverse effect of the fields was studied by densitymatrix equations of motion in an open Vtype system and Hurwitz criteria.The result shows that comparing with the case in the plane wave approximation,the transverse profile of the field leads to an obvious variation of the fashion that the system obtains inversionless lasing through instability of nonlasing solution,and makes the system more easy to obtain inversionless lasing through instability of pitchfork bifurcation;the value of the ratio of the active medium transverse section to the beam waist has a determinant effect on size of the instability region in which inversionless lasing arises,and the Raman inversion region increases with increasing of value of the ratio;the effects of unsaturated gain,loss of laser cavity,the ratio of atomic injection rates and atomic exit rate varying on the instability region in which inversionless lasing arises are much different from that in the plane wave approximation case.更多还原