Absorption linewidth measurement of reactive molecular electrinic states by nonlinear optical spectroscopy.

我们用XeCl准分子激光结合二次谐波晶体对连续波Ti：蓝宝石激光器输出进行脉冲放大，产生了线宽为200MHz的高分辨率紫外光。线宽仅为商用脉冲染料激光器的五分之一，可用于吸收光谱的精确线宽测量。为了研究膨胀烧蚀等离子体中离子的平移运动，我们利用紫外光测量了氧气氛下激光烧蚀产生的SiO^+吸收光谱的多普勒线宽。通过分析，我们再现了理论计算所期望的烧蚀等离子体振荡。我们将用这个系统来进行反应电子态的光谱研究。

We have produced high resolution UV light of 200MHz linewidth by a pulse anplification of the output of a CW Ti : Sapphire laser with a XeCl excimer laser conbined with a second harmonic crystal. The linewidth is only one fifth of the commercial pulsed dye laser and it will be highly effective for the precise linewidth measurement of absorption spectra.By using this UV light, we have measured Doppler linewidth of the absorption spectra of SiO^+ produced by laser ablation under oxygen atmosphere in order to investigate translational motion of ion in expanding ablation plasma. From the analysis, we have reproduced oscillation of ablation plasma which was expected from theoretical calculation.We are going to use this system for the spectroscopic study of reactive electronic states.