The development of surface finishing and coating technology at 10.6 µm for polycrystalline ZnSe laser windows is presented. Optical evaluation of the coated windows shows that the 10.6-µm absorption and reflection can be held to less than 0.1% per surface. Surface finishing procedures, theoretical coating designs, and recent experimental results for antireflection coatings for ZnSe are presented.
J. E. Rudisill, M. Braunstein, and A. I. Braunstein, "Optical Coatings for High Energy ZnSe Laser Windows," Appl. Opt. 13, 2075-2080 (1974)