Firstly, a telescope system is made up with a concave lens and a long-focus convex lens, by which the angle of the parallel beam from the collimator can be change.

该方法借助一个焦距较长的凸透镜与被测凹透镜组成无焦系统，可以使准直管出射光束的张角发生改变；

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Among the reshaping systems converting a Gaussian beam to a flattop beam, the system composed of a plane-concave and a plane-convex lens, is a relatively simple structure.

在将高斯光束整形为平顶光束的整形系统中，由两个非球面镜组成的系统是比较简单的结构形式，该系统由平凹镜和平凸镜组成。

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