中文摘要：

针对高倍率扩束系统设计要求（即轴上和轴外像差都得到较好的校正），从三级像差理论出发，设计了一种新型的40^×高倍率激光扩束系统。该系统是基于简单的伽利略结构并通过二级扩束系统来实现的，系统包括4片透镜，通过引入2个二次非球面、2个反射镜或1个棱镜来折叠光路。利用CODEV光学设计软件给出了该系统的光学结构参数和外形结构图，并进行了像质评价。结果表明：该系统结构简单，设计难度小，成本较低，像质好，性能优良，是一种可以被广泛采用的高倍率激光扩束系统。

英文摘要：

A new laser beam expander with magnification of 40^× as well as on-axis and off-axis aberration corrected properly, was designed based on the third-order aberration theory. This system is realized by two-step beam expanding based on a simple Galilean structure. The beam path of the system is folded by four lenses, two second-order aspheric surfaces and two mirrors （or a prism）. The optical mechanical parameters, outline drawing and image evaluation are given by the aid of optical design software CODE V. This system features simple design and structure, low cost, high image quality and good performance.