Amorphous Nitride Films as Improved Optical Coatings

Amorphous wide bandgap semiconductors are a promising system upon which to base optical coatings. Due to their ruggedness, excellent adhesion, smoothness and the ability to tailor the thermal expansion coefficient and index of refraction by changing thegroup III material, these materials should make excellent coating for beryllium optics. In this STTR program Nanohmics, along with their University partner, Ohio University, proposes to produce high quality optical coatings from sputtered amorphousnitride material. In Phase I wide bandgap nitride semiconductor amorphous films deposited on beryllium will be examined to demonstrate that this material can be used as high quality, adherent and smooth reflective coatings. Thermal conductivity and indexof refraction measurements will also be made on as deposited films. Phase II will apply these coatings to a commercial product and develop a commercial grade process to coat the optical material. Development of a commercial amorphous nitride coatingprocess will not only improve the manufacturability and quality of beryllium based optics but will improve the quality of more standard optical components by developing a new and improved coating technology for these materials.