IR Transmitting Aspheric Window Optics from Spinel Ceramics

MER plans to produce 12 diameter hyper-hemispherical domes and 10 diameter aspheric lenses of transparent spinel for the optic purposes during this program. Spinel was chosen because of its properties such as high transmission in the UV-Vis and Mid-IR wavelength range of 0.2 5.5 m, it is very resistant to abrasion, with density higher than 99.95% of theoretical, with very fine and uniform grain size exhibiting an average flexural strength close to 200+ MPa. MERs novel and proprietary process consisting of freeze forging, hot pressing and hot isostatic pressing creates close to net shape blank of from which a final part can be render and polished. The final polished part shows low birefringence, high transmission and refractive index homogeneity better than 10 ppm over a 160 degree aperture. To perform this program MER will design and develop all the tooling required to produce 12 diameter hyper-hemispherical domes and 10 diameter aspheric lenses, perform the sintering process and deliver finished optically polished parts to the program manager.