我要設計一個激光擴束鏡，要求正向使用（擴束）和反向使用（縮束）時產生的像差相同。請問采用什么樣的結構才可以實現？ bp'\nso/  
  最好是伽利略結構的（無實焦點），實在不行的話也可以用開普勒結構。

用伽得俐略的系統(tǒng)是比較長用的,這樣做的系統(tǒng)畢較短

There are lot, depending on your requirements. Anyway you can try: ue -a/a  
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1, Refractive: an achromatic as positive + plano-convex as negative; 9 xFX"_J  
OR 7|<-rjz^  
2, Reflective: two parabolic mirrors; 58]t iP"  
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Both of them affer nice spherical aberration performance. vAtR\Vh  
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Reminder: compute the laser beam density, ensure you have enough strong optical coating. .K+5k`kd