0.351μm激光辐照Au盘靶吸收、散射规律的实验研究

ABSORPTION AND SCATTERED LIGHT OF GOLD DISKS IRRADIATED WITH 0.351μm LASER LIGHT

在“星光Ⅱ”激光装置上，利用８０只分立式探测器研究了约０８ｎｓ，０３５１μｍ激光辐照Ａｕ盘靶的吸收、散射．结果表明，强度约为５×１０１４Ｗ／ｃｍ２的激光以１０°角入射，吸收可达９０％以上；但是，以４５°角入射，吸收仅为７５％左右，散射高达２５％．散射主要来自未被等离子体充分吸收的激光在弯曲临界面上的反射，同时伴随少量受激布里渊散射．吸收的理论计算与实验结果进行了比较，两者符合较好．

The experiments used the “Xingguang Ⅱ” laser facility to irradiate gold disks at some chosen angle of incidence. In this paper, we report the absorption and angular distribution of scattered lights of 0.351μm laser light by Au disks. The experiments have shown that the absorption by Au disk is higher than that irradiated with 0.53 or 1.05μm laser light. The angular distribution of scattered lights proves that scattered lights include stimulated Brillouin scattering and specular reflection from critical surface. Based on inverse bremsstrahlung absorption, the absorption obtained by simulation agrees with the experimental results.