Materials with Wideband Transmissivity

Current state-of-the-art infrared countermeasure (IRCM) systems require wider bandwidth lasers. As such, domes for these systems require high transmissivity in the region 300 nm8500 nm. Current IR dome materials, such as sapphire or Y2O3:La, exhibit sufficient transmission to 300 nm (as expected for these wide band gap materials), but do not meet the IR transparency requirements. By contrast, ZnS domes exhibit sufficient transmission to wavelengths longer than 8500 nm, but ZnS also absorbs in the near UV. To satisfy the wideband transmissivity requirement of next generation IRCM systems, new materials must be developed and novel methods to discover these materials must be employed. Lumenari proposes to use a combination of supercomputing and experimental methods to rapidly screen optical and mechanical properties of crystalline materials to elucidate UV and IR absorption cutoff wavelengths, as well as factors contributing to durability, coefficient of thermal expansion and water/air stability. This proposed approach will simultaneously maximize the probability of success and minimize the cost-per-material investigated. The work conducted in this Phase I project will yield a number of materials synthesizable in high purity at large quantities that are compatible with the IRCM transmission and durability requirements.