Extremely Uniform, Very Low Absorption Coatings for Large Aperature Optics

"Emerging laser weapon systems require extremely uniform, defect free, coatings applied to optics in excess of 1-meter in diameter. Multilayer dielectric coatings have been developed to provide high reflectivity and very low absorption for high power laserbeams. However, many of the best theoretical coating designs currently cannot be effectively manufactured because of the inability to precisely control the thickness of individual coating layers.Surface Optics Corporation (SOC), in conjunction with Schafer Corporation, propose to demonstrate a very low absorption (VLA) coating process capable of achieving extreme uniformity (< 1% thickness variation) for mirrors up to 2.5 meters in diameter. Theproposed innovation combines Surface Optics' 3.3-meter in-situ, motion-controlled coating chamber with Schafer's masking and thin film design capabilities. This innovation would create a unique capability in the United States, and would not requirecapital investment, as all of the manufacturing components are currently operational.Schafer Corporation is recognized for pioneering VLA coating technology for chemical lasers. By employing Schafer's mask design technology with SOC's motion controlled evaporation system, coating designs that require less than 1% film uniformity can becreated on large substrates, for the most demanding high power laser applications. By improving the uniformity of optical coatings to better than 1% over large are