摘要
介绍以惰性气体Xe为非线性介质、利用双光子共振四波混频差频方法产生的可调谐真空紫外激光(VUV)的特性研究 .实验中 ,传播方向和空间均相互重合的两束脉冲染料激光经透镜聚焦于Xe气混频池内 ,其中一束激光的波长 (2 4 9.6 2 6nm)对应于Xe原子 6P[1/2 ,0 ]←← 5P的双光子共振跃迁 ,通过调谐另一束激光的波长 ,产生在 15 1～ 171nm可连续调谐的VUV激光 .经估算 ,产生的VUV激光的强度约为每脉冲约 0 .2 μJ ,转换效率约为 0 .1% .通过测量超声射流冷却下CO分子的A1Π←X1Σ+ (0 ,0 )带的转动分辨激光诱导荧光 (LIF)光谱 ,确定出VUV激光的线宽为 0 .3cm-1.此外 ,还对VUV激光强度与惰性气体压力、染料激光强度等依赖关系进行了研究 .
The character of tunable Vacuum-Ultraviolet (VUV) laser generated by two-photon resonant four wave difference frequency mixing in Xenon was studied. The intense VUV laser was generated in the wavelength range of 151～171 nm using 6P\ level of Xe atom as the two-photon resonant state. The pulse intensity of VUV laser was estimated to be 0.2 μJ, and the conversion efficiency relative to the wavelength-fixed laser was determined to be 0.1%. The line width of VUV laser was found to be 0.3 cm -1 from the laser-induced fluorescence spectrum of A-X (0, 0) rotational line profiles of jet-cooled CO, which was much broader than those of the two employed dye lasers (0.1 cm -1), mainly due to the saturation broadening of Xe level by intense laser field. The dependencies of VUV intensity on Xe pressure and two dye laser intensities were also investigated in this experiment.
基金
ProjectsupportedbytheStateKeyDevelopmentProgramforBasicResearchofChina(G1999075304)andtheNationalNaturalScienceFoundationofChina(20373066)
