小型脉冲光泵NH_3分子远红外激光的Raman频谱研究

Study on Raman Spectrum of Miniature Pulsed Optically Pumped NH_3 Fir Laser

通过求解量子系统的密度矩阵方程 ,采用迭代法计算了在 TEA CO2 - 1 0 R(6)泵浦下 ,小型脉冲光泵 NH3分子远红外激光器中 ,NH3分子的 V2 :a→ s R(0 ,0 )跃迁和 a→s Q(5,4)跃迁的频谱特性。理论计算结果表明 ,对于 a→ s R(0 ,0 )跃迁 ,当工作气压比临界值 Pc高或泵功率密度比临界值 Ipoc低时 ,将出现 Raman频谱尖峰 ;对于 a→ s Q(5,4)跃迁 ,不出现频谱尖峰。频谱尖峰现象的根源是 AC Stark分裂的双光子相互作用的结果。

By solving the density matrix equation of quantum system,the spectral characteristics of V 2:a→sR(0,0) and V 2:a→sQ(5,4) transition in a miniature pulsed optically pumped NH 3 far infrared laser was calculated by means of iteration method.Which was pumped by TEA CO 2 10R(6) line.The results of theoretical calculation showed that the spikes in raman spectrum of V 2:a→sR(0,0) would appear,when the operating NH 3 gas pressure was higher than a certain critical value or pumping power density was lower than a certain critical value.The spikes could not appear for spectrum of a→sQ(5,4)transition.Which was caused by raman processes interaction of AC Stark splitting.