Research on ultrashort-wavelength vacuum ultraviolet generation by using stimulated Raman scattering

我们提高了CsLiB_6O_（10）（CLBO）的激光损伤容限，并尝试构建190 nm以下的真空紫外（VUV）激光源作为反斯托克斯（AS）受激拉曼散射（SRS）的新泵浦源。利用Nd：YAG激光器，通过几个频率转换阶段，产生了1697.9nm的五倍频和红外OPO。在最后一级，在CLBO中通过五次谐波与IR的和频产生产生低于190 nm的VUV光。从213 nm输入产生189 nm输出，转换效率为7.3%。在此基础上，我们采用20 W高峰值功率密度Nd：YAG激光器，设计了185 nm真空紫外激光系统。虽然我们目前正在构建系统的最后一级，但我们估计在185 nm处的平均功率超过100 mW，并预计在172，150和115 nm处的第1，第3和第8条AS线等H2中SRS的超短波长VUV辐射。

We have improved laser-induced damage tolerance of CsLiB6O10 (CLBO), and attempted to construct vacuum-ultraviolet (VUV) laser source below 190 nm as a new pump source of anti-Stokes (AS) stimulated Raman scattering (SRS). By using an Nd:YAG laser, the fifth harmonic and infrared (IR) OPO at 1697.9 nm were generated via several frequency conversion stages. At the final stage, VUV light below 190 nm was generated by sum-frequency generation with the fifth-harmonic and IR in a CLBO. A 189 nm output was produced with a conversion efficiency of 7.3% from the 213 nm input. Based on the experimental result, we have newly designed VUV laser system at 185 nm using a 20-W Nd:YAG laser with high-peak power density. Although we are currently constructing the final stage in the system, we estimate the average power over 100 mW at 185 nm and expect ultrashort-wavelength VUV radiation by SRS in H2 such as 1st, 3rd, and 8th AS lines at 172, 150, and 115 nm.