Corrosion-Resistant AR Coating of High Energy Alkali Laser Components Using Refractory Materials

Realization of high-performance compact lasers will require the development of substrates and advancements in optical coatings that can withstand the harsh environments of corrosive gases, high temperatures, and high energy densities. Toward this end we intend to undertake the development of novel optical coatings that will simultaneously provide the necessary protection and maintain the optical performance of coated components to the desired levels. The significant expertise of Radiation Monitoring Devices (RMD) and our sibling company Evaporated Metal Films (EMF) in designing, developing, and manufacturing advanced thin films and optical coatings will be used to realize the desired technology. Specifically, the proposed multi-layer index-matching coating(s) will be designed to ensure maximum transmission and minimum reflectance at the D1 and D2 wavelengths of Rubidium. Furthermore, its chemical structure will be resistant not only to Rb vapor, but also to its oxides and hydroxides. Computer modeling of the layered structure will be performed to study its light transmission properties. During Phase I, the efficacy of our approach will be demonstrated by coating sapphire substrates used in Diode Pumped Alkali Laser Systems (DPALS). To facilitate technology transition to commercialization we have teamed with a well-known company currently developing DPALS for commercial use.