连续泵浦准分子宽带泵浦碱金属激光器泵浦阈值理论研究

基于四能级受激准分子宽带泵浦碱金属激光器（XPAL）的工作机理建立了连续波半导体激光器泵浦的四能级XPAL理论模型,该模型基于速率方程,考虑泵浦光线宽与伴峰吸收线宽,采用迭代算法求解,主要用于分析半导体激光器连续泵浦四能级XPAL系统的泵浦阈值特性。讨论了温度、蒸气室长度、泵浦光线宽、输出耦合率和惰性气体粒子数密度对泵浦阈值的影响,结果表明激光器存在一个最佳温度可以使泵浦阈值达到最小,且在最佳温度附近较大范围内泵浦阈值不会有较大变化。除此之外,对蒸气室长度、输出耦合率、泵浦光线宽和惰性气体粒子数密度的分析表明,相较于惰性气体粒子数密度,其他参数的变化对泵浦阈值的影响较小。而较高的惰性气体粒子数密度可以有效提升增益介质对泵浦光的吸收从而降低阈值。

Simulative investigation of the threshold characteristics of CW pumped four-level XPAL system

This paper presents a continuous wave exciplex pumped alkali laser (XPAL) four-level theoretical model ,which can simulate the pump threshold. The model is based on rate equation and calculated by the iterative algorithm. The pump threshold characteristics of CW pumped four-level XPAL system can be analyzed by this model. The analysis of the influences of temperature, the length of the vapor cell, linewidth of pumped laser, output coupler and the concentration of noble gas on pump threshold are presented. It is shown that there is an optimal temperature which will keep a low threshold. In addition, the analysis of the length of cell, output coupler, linewidth of pumped laser and the concentration of noble gas shows that the influence of the concentration of noble gas on the pump threshold is larger than other factors. Larger concentration of noble gas can increase the absorption of pump laser in gain medium.