There are lot, depending on your requirements. Anyway you can try:
e-sMU
(~?P7RnU%
1, Refractive: an achromatic as positive + plano-convex as negative; 5JK{dis]k
OR Q1 mz~r
2, Reflective: two parabolic mirrors; ^2mmgN
x/{
Both of them affer nice spherical aberration performance. yBXdj`bV
A7>0Pn%D3
Reminder: compute the laser beam density, ensure you have enough strong optical coating. S)Sv4Qm
7G.IGXK$
Good luck.