Plastic Optical Glass From Elemental Sulfur Feedstocks

ABSTRACT Recent advances in sulfur polymer chemistry of elemental sulfur (S 8 ) feedstocks have enabled the emergence of a new class of plastic optical glasses spanning applications from visible (VIS) wavelength photonics to long‐wave infrared (LWIR) imaging. In contrast to conventional optical polymers, S 8 ‐derived polymers exhibit elevated refractive indices, broadband optical transparency, and favorable processing characteristics. This mini‐review summarizes recent developments in sulfur‐derived plastic optical glasses prepared through inverse vulcanization (IV) and sulfenyl chloride inverse vulcanization (SC‐IV) polymerizations. Inverse vulcanized glass (IVG) prepared from ultra‐high purity elemental sulfur afforded novel broadband VIS–LWIR plastic optics with high refractive index (RI, or n ≈ 1.9) and covalent adaptable network behavior. Extension of sulfur polymer chemistry to disulfide glass (DSG) materials derived from sulfur monochloride (S 2 Cl 2 ) enabled precision optical manufacturing of VIS‐IR transparent thermosets exhibiting reduced visible coloration, low optical attenuation, and compatibility with precision optics fabrication. Further development of photocurable disulfide methacrylate resin (DSMR) systems afforded a high refractive index photopolymer disulfide glass (Photo‐DSG) compatible with UV curing, microfabrication, and vat photopolymerization 3D printing workflows. These demonstrations establish sulfur‐derived polymers as a broader family of manufacturable plastic optical glasses bridging commodity sulfur feedstocks with emerging optical and photonic manufacturing technologies.