用于大气消光系数测量的组合棱镜吸收池设计

基于两棱镜组合的光学特点提出了一种改进的光振荡装置。该装置由四个直角棱镜组成，通过调节棱镜间的相对距离和位置，可以改变基线长度和振荡次数，使光线在光振荡装置中实现立体分布，达到增加光程的目的。通过测量输出光强度，得到大气消光系数和能见度；对实际应用中激光器发散角所引起的光传输过程中光斑直径随光程增加而增大的情况进行了数值模拟，并分析了不同能见度对应消光系数及不同光程的光强衰减比，为探测器的选取提供参考。

A New Design of Rectangular Prisms Absorption Cell for Atmospheric Extinction Coeeficient Measurement

A new type of oscillation cavity is developed based on the optical characteristics of the combination of two rectangular prisms. The oscillation cavity consists of four rectangular prisms. The length of basic line and the number of oscillations were changed by adjusting the distances and locations of four rectangular prisms. So the optical length of the cell increased. The light intensity can be measured by photoelectric conversion, so a ratio and the new equation of calculating atmospheric visibility can be obtained. Because of the divergence angle of of lasers, the diameter of the beam grows when the optical length increases. The situation is given by numerical simulation. The extinction coefficients corresponding with the different atmospheric visibilities are analyzed. The light intensities are calculated when the light pass the different optical lengths. This can provide reference for the selection of a detector.