MWIR-LWIR dual-band imaging system with hybrid refractive-diffractive-metasurface optics for spatially separated focal planes

The integration of mid-wave infrared (MWIR) and long-wave infrared (LWIR) imaging into a compact high-performance system remains a significant challenge in infrared optics.In this work, we present a dual-band infrared imaging system based on hybrid refractive-diffractive-metasurface optics.The system integrates a silicon-based metalens for the MWIR channel and a hybrid refractive-diffractive lens made of high-refractive-index chalcogenide glass for the LWIR channel.It achieves a compact total track length (TTL) of 11.31 mm.The MWIR channel features a 1.0 mm entrance pupil diameter, a 10f ield of view (FOV), and achromatic imaging across the 3-4 m spectral range with a focal length of 1.5 mm.The LWIR channel provides an 8.7 mm entrance pupil diameter, a 30FOV, and broadband achromatic correction over the 8-12 m spectral range with a focal length of 13 mm.To further enhance spatial resolution and recover fine image details, we employ low-rank adaptation (LoRA) fine-tuning within a physics-informed StableSR framework.This hybrid optical approach establishes, to our knowledge, a new paradigm in dual-band imaging systems by leveraging the complementary advantages of metalens dispersion engineering, diffractive phase modulation, and conventional refractive optics, delivering a lightweight, multispectral imaging solution with superior spectral discrimination and system compactness.