Novel Very Fast Tunable Filter for Hyperspectral Imaging

This program addresses an opportunity to develop unique electronically tunable filters for multi- and hyperspectral imaging with characteristics that surpass all other present tunable filter technologies. The approach is based on holographically formed polymer dispersed liquid crystal material that were under development at Brown University for display and telecommunication applications. The H-PDLC constitute a stack of polymer and liquid crystal layers whose index of refraction can be changes by the application of electrical potential, thus changing the optical properties of the stack. The operating requirements for displays and telecommunications, under development for several years at a significant level of funding, are vastly different from the requirements for tunable filter based sensors. The Phase-I STTR investigation, therefore, focused on identifying H-PDLC properties that need to be tailored to meet sensor requirements, and on developing technical approaches to implement such changes. We have successfully completed this evaluation and developed plans for a series of modifications including special tailoring of material, assembly process changes and control steps, addition of other additives, etc., all of which will lead to a filter with the correct properties for the sensor applications. Under Phase-II, H-PDLCs optimized for multi- and hyperspectral sensor applications will be assembled and incorporated into sensor prototypes for laboratory and field testing.