Understanding Optical Coatings For Military Applications

By Trey Turner, Chief Technology Officer, REO

Virtually all optical components used in military applications, such as target designation, rangefinding and IR countermeasures, employ thin film coatings to somehow modify their transmission and reflection characteristics. Yet, despite their ubiquity, many military system designers are not familiar with the commonly encountered tradeoffs in thin film design, or with the characteristics of various coating deposition technologies. As a result, optical coatings are often specified in ways that drive up cost unnecessarily. This article reviews some of the most important design and deposition factors. It is intended to help those who specify optical coatings establish a realistic set of specifications that deliver the necessary performance in the most cost-effective manner.