There are lot, depending on your requirements. Anyway you can try: #+DmH 'I01F:` 1, Refractive: an achromatic as positive + plano-convex as negative; &.bR1wX OR C9;X6 2, Reflective: two parabolic mirrors; x)qHeS ?0)XS< Both of them affer nice spherical aberration performance. r(xlokpnb6 hZ / Reminder: compute the laser beam density, ensure you have enough strong optical coating. <cS7L0h W/F4wEODY Good luck.
Hi, Tq_X8X#p K1{nxw!` The following is a link of technical data of optical adhesives, hope it be helpful: F3|pS: adPU)k_j: http://www.lienhe.com.cn/uvadh/NOA60.htm zZ0V6T} Zgf||, Double check from your lens vendor waht type of adhesive they use for your cemented doublet. K[yJu 4 F,2#;t4 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. EKJ4_kkjM yzzre>F Again, good luck.