Phys.org  May 29, 2023 There is a need for low-cost alternatives to traditional materials used in infrared optics such as germanium. Sulfur-rich copolymers hold promise, as they are made from low-cost feedstocks and have a high refractive index. Researchers in Australia copolymerized cyclopentadiene with sulfur to provide a plastic with the highest long-wave infrared transparency reported to date for this class of materials. Diverse lens architectures were accessible through melt casting or reactive injection molding. The featured copolymer was black, which enabled its use as an infrared-transparent blind for protection of thermal imaging equipment and clandestine surveillance. According to the […]