基于氟橡胶圈密封测试了熔石英真空窗口在351 nm激光辐照下的激光诱导损伤阈值（LIDT），实验发现真空窗口和氟橡胶圈紧密接触后LIDT下降约50%，氟橡胶圈经多次挤压后，其对真空窗口LIDT的影响显著减弱，在此基础上对比了大气、10³ Pa和10⁻²～10⁻¹ Pa下真空窗口的LIDT，结果显示随着气压降低真空窗口LIDT显著下降且气压再次升高后其LIDT未有提升。基于铟丝密封对比测试了真空窗口在不同气压下的LIDT，结果未发现气体含量差异对真空窗口LIDT的影响。对比两种密封材料测试结果，认为真空窗口LIDT下降是由氟橡胶圈污染引起，且低气压下有机物释放加剧。

宽带光打靶可以有效降低激光等离子体相互作用过程中非线性效应。提出一种基于角色散的非共线匹配宽带三倍频方案，利用宽带基频与窄带二倍频的非共线和频产生宽带三倍频，和频过程中通过特殊设计的渐变光栅实现不同频率的基频光束以特定角度入射，补偿了波长差异引入的位相失配使得全波段满足位相匹配条件。理论模拟表明，采用KDP晶体Ⅱ类位相匹配，将中心波长为1058 nm、带宽10 nm的宽带基频光与526.5 nm的二倍频光进行非共线匹配和频，可以实现高效宽带三倍频转换。

Fifth harmonic generation (5th HG) of a Nd:glass laser is an effective way to acquire high-energy coherent deep-ultraviolet radiation near 200 nm. In this work, cascade generation of the fifth harmonic of a Nd:glass laser in a 5 mm ammonium dihydrogen phosphate (ADP) crystal was investigated, and maximum conversion efficiency of 14% and large angular acceptance of 45 mrad were demonstrated at a noncritical phase-matching temperature of 75.1°C. However, as the results reveal, the temperature sensitivity and nonlinear absorption would hinder its high-energy application. As for that, based on the complementary relationship of the angle and temperature in the phase-matching condition, an upgraded focusing 5th HG design coupled with the cylindrical temperature distribution scheme was proposed. By this upgraded focusing design, more than the improvement of the conversion efficiency, the output 5ω near-field intensity distribution turns out to be insensitive to the temperature gradient. Potentially, this idea can be applied for many other frequency conversion schemes such as high-repetition frequency lasers, which have similar temperature gradient problems.