Dual Band Mirror System on Flexible Membrane for High Energy Laser Applications

Emerging laser defense systems require defect free coatings applied to flexible membranes in excess of 2-meters in diameter. Surface Optics Corporation (SOC), in conjunction with SRS Technologies, propose to develop a 3.0-meter polymer membrane mirror for high-energy laser applications. In Phase I, the feasibility of applying complex dielectric mirror structures to small polymer membranes was demonstrated. In Phase II, scale-up issues such as the ability to achieve exceptional coating uniformity over large areas will be addressed. SOC will develop and demonstrate a novel deposition technique to achieve +/-2% coating uniformity over a 3.0-meter substrate. The proposed approach is based on SOC's unique, computer controlled evaporation positioning system. SOC will also implement a new method to optically monitor a large substrate using a hyperspectral imaging camera. SOC will optimize the HEL performance of Ta2O5 and SiO2 films by reacting ionized oxygen with various sub-oxide tantala and silica species. The effect of using various starting materials on coating density, coating contamination level and laser damage threshold will be characterized. Membrane transmission properties will be tailored to match the requirements of the HEL coating design by varying the polymer membrane composition.