基于分子振动弛豫理论完善了缓冲气体的作用模型,利用半经典密度矩阵理论与量子力学理论,定量分析研究了缓冲气体对小型光抽运远红外激光过程的作用机理以及缓冲气体作用下小型腔式光抽运NH3分子远红外激光器的频谱特性,讨论了工作气压、抽运功率等工作参数对频谱特性的影响,并对理论计算结果进行了实验验证,二者符合得较好。研究结果表明,在小型光抽运远红外激光器中加入适当的缓冲气体,大量工作气体分子与缓冲气体分子之间的无规碰撞会引起谱线加宽,而且可以使远红外激光输出信号增强。

Based on the theory of vibrational relaxation, the buffer gas mechanic model is developed. The mechanism of buffer gas and spectrum characteristics of optically pumped miniature cavity NH3 far-infrared laser are calculated by semi-classical density matrix theory and quantum mechanics theory. The effects of operating gas pressure and pumping power on spectrum characteristics are studied quantitatively. And the theoretical results are verified by the experiments. The results shows that the spectrum of far-infrared laser can be widened when certain buffer gas is added into the laser medium, and the output power of far-infrared laser increase too.