There are lot, depending on your requirements. Anyway you can try: fngZ0k! 2~]c`/M3 1, Refractive: an achromatic as positive + plano-convex as negative; H`@x5RjS OR hDp'=}85@ 2, Reflective: two parabolic mirrors; _5y)m5I ITbl%q Both of them affer nice spherical aberration performance. 5@ZD' 7^Onq0ym T Reminder: compute the laser beam density, ensure you have enough strong optical coating. IHagRldG wRie{Vk Good luck.
Hi, $6oLiYFX; jJ?3z,h The following is a link of technical data of optical adhesives, hope it be helpful: |`O7>(h R6AZIN: http://www.lienhe.com.cn/uvadh/NOA60.htm ,[Ytl 6s|C:1](b Double check from your lens vendor waht type of adhesive they use for your cemented doublet. i,bFe&7J Z3#3xG5pl It is OK to use the spaced doublet design as a backup, if so, please pay a lot attention on the opto-mechanical design and assembling. E|^a7-}| zxsnrn;| Again, good luck.