There are lot, depending on your requirements. Anyway you can try: #}t1 X$uz=) 1, Refractive: an achromatic as positive + plano-convex as negative; )Vg{Y [! OR >xU72l#5 2, Reflective: two parabolic mirrors; ,p*ntj{ VO @
4A6 Both of them affer nice spherical aberration performance. $ gr6 `hK>bHj Reminder: compute the laser beam density, ensure you have enough strong optical coating. ^`TKvcgIc Ft"&NtXeZZ Good luck.
Hi, kO..~@aY ^Hz The following is a link of technical data of optical adhesives, hope it be helpful: /`4v"f0V k\+y4F8$x http://www.lienhe.com.cn/uvadh/NOA60.htm (<]\,pP0_ ;1*m}uNz Double check from your lens vendor waht type of adhesive they use for your cemented doublet. r6F{ B91S
h` 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. 5T$9'5V7 iioct_7,g< Again, good luck.