光泵NH_3分子亚毫米波激光的模式竞争  

Mode Competition in Optically Pumped NH_3 Sub-Millimeter Wave Laser

作　　者：罗锡璋[1] 陈伟斌[1] 丘茹曼[1] 

机构地区：[1]中山大学电子与通信工程系,广东广州510275

出　　处：《中山大学学报（自然科学版）》2005年第6期29-31,共3页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：广东省自然科学基金资助项目(021757)

摘　　要：采用半经典密度矩阵理论研究了光泵NH3分子亚毫米波激光的P支跃迁(V2∶a→sP(5,4))和Q支跃迁(V2∶a→sQ(5,4))的模式竞争。推导了四能级系统的激光介质的增益表达式;采用迭代法,数值计算了不同工作条件下的P支跃迁和Q支跃迁的输出光强,得到了模式竞争的规律:在压强较低的情况下,P支跃迁占优势;在压强较高情况下,Q支跃迁占优,但光强很弱并受到严重的自吸收效应所抑制。计算结果与实验相符。Based on the semi-classical density matrix theory, mode competition between V2： a→sP （5, 4） （P- transition） and V2： a→sQ （5, 4） （Q-transition） in optically pumped NH3 sub-millimeter wave laser （SMMWL） was studied. The gain coefficients of laser media in a four energy-level system were deduced. The output powers of Po transition and Q-transition were numerically calculated by means of iteration method under different operating conditions. The rules of mode competition can be summarized as follows： In low operating gas pressure condition, P-transition was in dominant position; while in high gas preasure conditin, Q-transition domninated, but much weaker and was restrained by serious self-absorption of SMMW laser. The calculated results were verified by our experiment.

关 键 词：亚毫米波 光泵亚毫米波激光 模式竞争 

分 类 号：O433.54[机械工程—光学工程]