提高PIV片光源质量的研究  

On The Improvement of PIV Light Sheet Quality

作　　者：钟强[1] 陈启刚[1] 王兴奎[1] 李丹勋[1] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084

出　　处：《实验力学》2013年第6期692-698,共7页Journal of Experimental Mechanics

基　　金：国家自然科学基金(51127006)

摘　　要：根据高斯光束的性质,本文设计了一种利用普通连续激光器产生较高质量PIV片光源的光路系统。整个光路分为两部分,第一部分为原始光束优化光路,第二部分为片光分光光路。原始光束优化光路通过一系列凸凹透镜有序布置,将原来直径大于2mm的光斑在PIV实验区间控制到1mm以下。优化光路能有效集中激光能量,提高片光亮度。片光分光光路使用鲍威尔棱镜将激光光束分为扇形片光,再用平凸柱面镜将扇形片光汇聚为矩形片光。鲍威尔棱镜分得片光的能量在宽度方向分布较常规双凹柱面镜均匀。平凸柱面镜将扇形光源中分散在极宽区域的能量集中在固定宽度里,使得激光能量的有效利用率提高,有利于PIV实验。An optical system using common continuous laser was designed to produce higher quality PIV light sheet based on the nature of the Gaussian beam. The entire optical path is divided into two parts： the original beam optimization part and light sheet generation part. The original beam optimization part optimizes the original beam through a series of concave and convex lens, which reduces the diameter of light spot from 2 mm to less than lmm. The optimization path can effectively concentrate .the laser energy to improve the brightness of light sheet. Triangular prism is used in light sheet generation part to divide the laser beam into a fan-shaped light sheet, and a planoconvex cylindrical lens is used to converge the fan-shaped sheet to a rectangular light sheet. The energy distribution along width direction of light sheet behind the triangular prism is more uniform than that of conventional double-concave cylindrical lens. Planoconvex cylindrical lens concentrates the laser energy into a fixed width from very wide area, which results in several times brightness of rectangular light sheet higher than that of fan-shaped light sheet.

关 键 词：粒子图像测速法(PIV) 连续激光 高斯光束 片光厚度 光斑直径 

分 类 号：O357.54[理学—流体力学]