卡塞格林望远系统与激光束参数匹配

 在激光工程系统中，把卡塞格林望远系统等效为一个扩束器和环形光阑的组合形式，研究了激光束的光腰半径与卡塞格林望远系统的参数匹配问题。推导出光束扩束后通过环形光阑衍射的场分布解析表达式，并由此数值计算了由环形光阑引起的能量损失，以及光束扩束后光腰半径与环形光阑外径的比值K对Strehl比的影响。结果表明，在卡塞格林望远系统参数确定的条件下，存在最佳比值K，使损失能量最小，并可以获得较高的Strehl比，得到最大的峰值光强。

Parameters matching between Cassegrain telescope system and lasers

In the laser engineering system, a beam expander and an annular aperture were taken as the equivalent of the Cassegrain telescope system. The far-field irradiance distribution of an expanded Gaussian beam which had gone through an annular aperture was deduced in an inner optical system. The energy loss and the effects of the ratio of Gaussian beam-waist radius after expander to outer radius of the annular aperture on Strehl ratio were numerically computed. The results show that an optimal ratio exists for least energy loss and high Strehl ratio on the condition of the definite parameters of the Cassegrain telescope.