Dual Band Infrared Coatings

Sensor performance for the 3rd Generation FLIRs can be substantially improved by increased simultaneous throughput of both mid wave (MWIR) and long wave (LWIR) sensor bands (3.5 – 5µm and 7.8 – 10.5µm) in the optical systems. Phase I addressed coating design and initial deposition for five of categories of optical components: anti-reflection (AR) coatings for refractive lenses, and fold mirror, beamsplitter, and cold filters, and the inside window AR. New gradient index design and fabrication techniques were developed. We designed and fabricated coatings for a variety of substrate materials including AMTIR-1, BaF2, GaAs, Ge, ZnS, and ZnSe. Results are very promising. The Phase II effort will continue development of the coatings, but with a focus on the issues of improved coating performance, characterizing (and improving, as necessary) environmental durability, fabrication on larger and/or curved surfaces, improved coating uniformity, process optimization, scale up to production quantities, and qualifying the coatings for Army applications.