Fabrication of Plastic Optics from Chalcogenide Hybrid Inorganic/Organic Polymers for Infrared Thermal Imaging

The development of infrared (IR) plastic optics for infrared thermal imaging, particularly, in the long-wave IR (LWIR) spectrum (7-14 mu m) is an area of growing technological interest due to the potential advantages associated with plastic optics (e.g., moldability and low cost). The development of a new class of optical polymers, chalcogenide-based inorganic/organic hybrid polymers (CHIPs) derived from the inverse vulcanization of elemental sulfur, has enabled significant improvements in IR transparency due to reduction of IR absorbing organic comonomer units. The vast majority of effort has focused on new chalcogenide hybrid polymer synthesis and optical property improvements (e.g., refractive index, Abbe number, and LWIR transmission); however, fabrication and IR imaging methodology to prepare optical components has not been demonstrated, which remains critical to develop viable IR plastic optics. A new methodology is reported to fabricate optical components and evaluate LWIR imaging performance of this emerging class of optical polymers. New diffractive flat optics with a Fresnel lens design for these materials have been developed, along with a basic LWIR imaging system to evaluate CHIPs for LWIR imaging. This system-based approach enables correspondence of copolymer structure-property correlations with LWIR imaging performance, along with demonstration of room temperature LWIR imaging. The fabrication of Fresnel lenses with chalcogenide hybrid inorganic/organic polymers made by the inverse vulcanization of elemental sulfur is demonstrated along with the development of a basic long-wave infrared (LWIR) imaging system to enable structure-property-imaging studies of new LWIR transmissive polymeric materials. Successful LWIR imaging with both supported thin film and free-form plastic optics has been demonstrated as well as LWIR imaging under ambient conditions.image