Characterization and testing of optical polymers for LWIR space flight applications

There is a growing need for more research into space-based technology. As more satellites are deployed and payloads are developed, it is important now more than ever to meet competitive size, weight and power (SWaP) requirements. For optical systems, optical polymers provide for a lightweight, broadband solution to this problem. Sulfur-based optical polymers have been growing in importance due to pioneering work at the University of Arizona over the last decade, with numerous research papers published on their unique properties and many other infrared optics groups investigating this material family. Not only do sulfur-based optical polymers have transmission from the visible stretching out into the longwave infrared (LWIR), but they also can be uniquely molded, allowing for the advancement of complex lens shapes, diffusers and metamaterials. In addition to this, the refractive index and optical transmission properties of the material can be tuned for different requirements. This allows for the possibility of making complex passive devices with a gradient index, such as gradient refractive index (GRIN) lenses. To qualify these materials for space-based applications, they must be demonstrated to satisfy a series of optical and mechanical standard tests. This paper explores the results of these tests and demonstrates that sulfur polymers are satisfactory for work in space-based environments.