There are lot, depending on your requirements. Anyway you can try: gg;&a(
S1 22.
I
1, Refractive: an achromatic as positive + plano-convex as negative; lq2P10j@
OR .PyPU]w
2, Reflective: two parabolic mirrors; FJ}RT*7_C
sFNB rL
Both of them affer nice spherical aberration performance. @eQIwz
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Reminder: compute the laser beam density, ensure you have enough strong optical coating. F?b5 !<5
vby[#S|
Good luck.