非链式HF激光器能量稳定性影响因素实验研究

为提高非链式电激励脉冲HF激光的能量稳定性,分析了激光产生反应动力学和影响激光能量稳定性的主要因素,得知基态HF分子的生成、工作气体的温度上升以及工作气体C2H6的消耗是激光能量快速下降的主要原因。经实验研究,没有采用任何反应产物去除方法的情况下,激光器输出1600个脉冲激光后,激光能量下降率达31%,采用沸石分子筛吸附单元对基态HF分子进行吸附后,同样输出1600个脉冲激光,激光能量基本趋于平稳状态,且输出约5500个脉冲激光后,激光能量较初始平均值仅有10%的下降;另外,在激光器运行过程中,恢复工作气体的初始温度和补充少量的C2H6也能改善激光能量的稳定性,其中补充25%的C2H6气体可使激光能量提高近8%。由激光产生反应动力学和实验研究结果可知,增加分子筛吸附单元、工作气体温控单元和工作气体实时补给单元可提高激光能量的稳定性。

Experimental investigation on factors influencing output energy stability of non-chain HF laser

In order to improve the output energy stability of non-chain discharge-pumped pulsed HF laser, the chemical reaction dynamics of the HF laser and key factors determining the output stability were analyzed. The combination of the generation of fundamental-state HF molecules, the rising temperature of gases and the consumption of C2H6 was responsible for the rapid decrease of output energy. Experiments were performed to verify the analysis, from which some conclusions could be drawn as follows. The output energy decreased by as high as roughly 31% of the starting value without eliminating of reaction products (i.e., the fundamental-state HF molecules), whereas the output energy was relatively much more stable with zeolite molecular sieve to adsorb the fundamental-state HF molecules after 1600 output pulses. The output energy decreasing ratio of the latter was only 10% after 5500 output pulses. In addition, temperature recovering of gain medium to the initial state, as well as the supplement of C2H6 into the cavity, was demonstrated to improve the stability of output energy. Quantitatively, supplement of C2H6 by 25% could improve the output energy by 8%. According to the chemical reaction dynamics and experimental results, the output energy stability is supposed to be improved by mounting the zeolite molecular sieve absorber, gases temperature controller and real-time gain medium supplement unit into the HF laser device.