Surfaces of both transmissive and reflective optical components are made of comparatively soft materials (plastics, optical glasses, halide crystals, infrared-transmitting materials, aluminum, silver) and vulnerable to scratching and chemical deterioration through environmental attack and abrasion in use and routine cleaning. A coating of cubic boron nitride (CBN), having a hardness comparable to diamond and high chemical stability, can greatly extend the useful lives of such components. A program of research, based on the experience and capabilities of artech in thin film deposition and instrumentation and the accomplishments of Dr. Charles feldman in production of pure bobon films at johns hopkins applied physics laboratory, is proposed to identify the most suitable process for applying cbn coatings to a wide range of optical surfaces. The program, with Dr. Feldman as consultant, will explore the use of vacuum evaporation in conjunction with ion beam technology as well as radio-frequency sputtering to deposite adherent cbn films on unheated substrates. Consultation on ion beam techniques and equipment will be provided by George J. Lutz, who has had continuous experience in that field beginning in 1969 with the first commerical ion milling apparatus. Equipment for practical applications will be developed in phase II.
