Abstract
Long-wave infrared (LWIR) imaging is widely used in night vision and thermal target recognition, but often suffers from noise and blurred edges. Here, we present a distributed Bragg reflector–liquid crystal (DBR-LC) framework for reconfigurable optical preprocessing of LWIR images. By combining the angle-dependent phase response of DBRs with the electrically tunable refractive index of an LC cavity, programmable spatial-frequency optical transfer functions are realized through angular-spectrum engineering. The framework enables switchable low-pass, high-pass, band-pass, and band-stop filtering for selective denoising and edge detection within a compact, low-power platform, establishing a foundation for reconfigurable optical computing and intelligent infrared imaging systems.