There are lot, depending on your requirements. Anyway you can try: ,9?'Q;20 > 7;JZuVo 1, Refractive: an achromatic as positive + plano-convex as negative; .Z_U]_( OR |o!<@/iH= 2, Reflective: two parabolic mirrors; `t6lnO g,,cV+ Both of them affer nice spherical aberration performance. ^iV@NVP lg8~`96 Reminder: compute the laser beam density, ensure you have enough strong optical coating. 2CmeO&(Qf* *r-Bt1 Good luck.
Hi, Q1jyetk~I BMdr.0 The following is a link of technical data of optical adhesives, hope it be helpful: 1B1d>V$* plf<O5' http://www.lienhe.com.cn/uvadh/NOA60.htm JfVayI= O Z#? Double check from your lens vendor waht type of adhesive they use for your cemented doublet. C$tSsw?A CD[7h 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. `Ch6"=t {[s<\<~B* Again, good luck.