Advanced Antireflective Coatings for Polycarbonate Lenses

ABSTRACT: Robust optical coatings are of great importance across a broad spectrum of applications. Hard, durable, stress-free coatings are needed and used in everything from ophthalmic polymers to infrared optics. One of the principal shortcomings of typical inorganic oxide, nitride, and sulfide coatings when applied to polymeric substrates is the large difference in the coefficient of thermal expansion (CTE) between the two types of materials. This mismatch in CTE leads to unwanted stress in the applied coatings resulting in a failure of the coating. To address the Air Force"s optical coatings requirements, Nanohmics is developing the tools and processes for producing optical coatings employing pulsed laser deposition and sputter-deposited amorphous nitrides and oxides. These materials enable coatings (reflective, antireflective, and bandpass) with high quality, excellent adherence, and compatibility with substrates including metals, polymers, and traditional optical materials. During this program, Nanohmics is proposing to develop a mixed organic/inorganic anti-reflective coating to be applied to polycarbonate-based ophthalmic lenses. The ultimate lenses will have a scratch-resistant, stress-free, adherent coating with transmission greater than 99.5% from 400 to 750 nm. BENEFIT: The developed processes and tools can be used to deposit reflective, anti-reflective, and bandpass coatings on to a variety of optical materials including polymers, glasses, and metals. Potential applications include lenses, windows, face shields, airplane canopies, solar panel coverglass, and building sheeting and glazing.