循环跃迁的Δ 型三能级系统中的无反转激光

研究了在引入非相干抽运的情况下,循环跃迁的Δ型共振三能级系统中产生的无反转激光.利用主方程的方法, 导出了缀饰态中强相干场极限下布居数项和相干项的稳态近似解析解以及产生无反转激光所需要满足的条件;并利用数值模拟的方法讨论了布居数分布、 系统增益对探测场和相干场拉比频率的依赖性以及随时间的演化规律. 结果表明:无论各个参量取何值,共振Δ型三能级系统总是处于无粒子数反转的状态; 只要探测场或相干场之中有一个为强场,便可产生无反转激光; 当其中任意一个场远强于另一个场时,系统的无反转增益将不再依赖于任何一个场的拉比频率.

Laser without inversion in a △-conflguration three-level system with cyclic transition

In the case of incoherent pumping,laser without population inversion in a resonant three-level A-configuration system is investigated.By taking the strong coupling field limit,we obtain the approximate steady-state analytical solution of populations and imaginary part of coherences within the dressed-state regime,and discuss the condition of the generating of laser without inversion and the dependences of population distribution and system gain on Rabi frequency of the probe and coherence fields.The results show that the resonant three-level A-configuration system is always in the state of no population inversion,and laser without inversion occurs if one of the two fields is strong.When one of the two fields is much stronger than the other one,the gain without inversion is independent of the two Rabi frequencies.