Infrared-Transparent, Electrically Conductive Coating

IR transparent windows and domes on aircrafts and missiles often provide other functionality, such as conductivity, through the use of coatings or metallic grids. For visible applications, conductive coatings like indium tin oxide are available; however, these coatings become highly absorbing at longer wavelengths. For MWIR applications, conductivity is generally provided by metal grids. Unfortunately, the grids are not transparent and produce scattering/reflections, and thus a suitable transparent conductive coating is preferable for applications like the targeting system in the Joint Strike Fighter. During Phase I, Surmet and Teledyne successfully fabricated a durable IR transparent, conductive coating. Teledyne applied their TransCon coatings on Surmet provided spinel substrates and Surmet applied a durable top layer. Measurements indicate that Surmet"s durable coating did not have a detrimental effect on the optics and conductivity of the TransCon-Spinel samples. The durable coatings were completely resistant to hot water and thermal cycle while maintaining some resistance to sand abrasion. This Phase II will further develop the coating technology to improve optical properties of the TransCon and make it valuable to a wider range of MWIR applications. Additionally, thicker durable layers will be evaluated to increase the abrasion resistance of the IR transparent conductive coating.