Advancing Beam Steering with a New Polarization-Insensitive Liquid Crystal Prism

The United States Air Force (USAF) through the STTR topic AF24D-T002 seeks a novel optical element that deflects light into a single, forward direction, like a Risley Prism, that is flat and thin. To address this need, Spectral Energies (SE) aims to advance the use of liquid crystals (LCs) for beam steering in the mid-wave infrared (MWIR) spectrum by developing a novel, polarization-insensitive prism device. Traditional Risley prisms suffer from high polarization sensitivity and narrow spectral bandwidth, limiting their practical applications. By utilizing cholesteric liquid crystals, which exhibit isotropic properties at longer wavelengths, we propose a device capable of achieving low-voltage operation and significant refractive index variations. The proposed solution aims to provide efficient transmission and broadband operation across a 3-5 µm spectral range, addressing the current limitations of liquid crystal gratings. During Phase I, SE will perform material characterization, fabricate a proof-of-concept flat prism, and demonstrate the capabilities of said prism. In Phase II the successful Phase I proof-of-concept will be expanded into prototype device that will be further tested and validated.