Cassegrain激光发射系统的光路设计

为了提高激光探测系统激光的发射功率，在出射激光为基模的高斯光束的光路设计中，根据高斯光束经过光学系统的变换与传输特性，分析了系统采用Cassegrain望远镜时，其遮拦比以及入射光束束腰半径对光功率透过率的影响。通过具体的数值计算得出，随着遮拦比及入射光束束腰半径的增大，系统光功率透过率将减小，给出了望远镜遮拦比与发射孔径处光斑尺寸之间的最佳匹配关系，最后讨论了离焦误差（安装误差）为0.2mm时对出射光斑尺寸的影响。

Optical path design for Cassegrain laser transmitting system

In order to improve the laser transmitting power of laser detection system, assuming exit laser is a fundamental mode Gaussian beam, the effect of the obscuration ratio of Cassegrain telescope and the waist radius of the incident light beam on the light power transmission was analyzed based on the transformation and transmission characteristics of Gaussian beam passing through the optical system. The numerical calculation indicates that the optical power transmission of the system decreases with the increase of the obscuration ratio and the waist radius of the incident light beam. The best match between the obscuration ratio and the spot size of the transmitting aperture was given. The effect of the defocusing error (installation error) of 0.2mm on the spot size of emergent beam was discussed.