Evaluation of sapphire at II-VI Optical Systems for HEL applications

There is an increasing industry need for high quality materials which can be used in high energy laser (HEL) applications. Currently, II-VI OS is growing large sapphire substrates for use in the defense industry on aerospace applications that operate in the visible and mid-wave infrared regions. II-VI OS is capable of producing a-plane and cplane sapphire substrates of sufficient size for envisioned HEL applications, and in the following paper will present optical and material data on properties of interest. Specifically, data will be presented on BTDF and BRDF at 1.06μm in both s- and p-polarizations at angles of incidence (AOI) ranging from 0 to 60 degrees. These measurements are performed on a-plane and c-plane windows grown, fabricated and polished at II-VI OS Additionally, other critical properties evaluated include absorption at 1.06μm, as well as thermal expansion coefficient and Knoop hardness of cplane sapphire.