There are lot, depending on your requirements. Anyway you can try: se|>P=/
[HRry2#s
1, Refractive: an achromatic as positive + plano-convex as negative; 0 ge"ISK
OR "_LDs(&
2, Reflective: two parabolic mirrors; CbvP1*1
968<yO]
Both of them affer nice spherical aberration performance. s9[?{}gd
:n#8/'%1
Reminder: compute the laser beam density, ensure you have enough strong optical coating. AnF"+<
FEC`dSTI
Good luck.