Fig. 1. Design and analysis of the hybrid optical system. (a) Optical design of the hybrid metalens. (b) Refractive index and transmittance of GGAT glass. (c) Transmittance of Si wafer. (d) Phase profile of the metalens for different wavelengths. (e) MTF analysis for the MWIR metalens without RL and DOE under different FOV angles. (f) MTF analysis for the MWIR metalens with RL and DOE under different FOV angles. (g) Phase profile of the DOE structures for different wavelengths. (h) MTF analysis for the LWIR lens without DOE structures under different FOV angles. (i) MTF analysis for the LWIR lens with DOE structures under different FOV angles.

Fig. 2. Metalens design. (a) Meta-atom. (b) The ideal phase distributions incorporating C(λ) corrections for different wavelengths. (c) The ideal (solid black lines) and the realized (red circles) phase distributions at 3.0, 3.2, 3.5, 3.7, and 4.0 µm. (d) The outer and inner radii of the meta-atoms across the diameter of the MWIR metalens. (e), (f) 2D view of the designed achromatic metalens and an expanded view of the circular cylinder in the marked area.

Fig. 3. Analysis of the PSF and RI of the MWIR imaging. (a) Normalized broadband PSF intensity distributions for the MWIR imaging under various FOV conditions. (b) Broadband MWIR PSF intensity distributions and the corresponding RI values across different image plane positions. (c) The spatially continuous FOV PSF array. (d) The ideal high-quality MWIR test pattern^[34] that is divided into a series of annular regions corresponding to different FOV angles. (e) Simulated MWIR imaging output.

Fig. 4. Analysis of the PSF and RI of the LWIR imaging. (a) Normalized broadband PSF intensity distributions for the LWIR imaging under various FOV conditions. (b) Broadband LWIR PSF intensity distributions and the corresponding RI values across different image plane positions. (c) The spatially continuous FOV PSF array. (d) The ideal high-resolution LWIR test pattern^[35] that is segmented into a series of annular regions corresponding to different FOV angles. (e) Simulated LWIR imaging output.

Fig. 5. Optimization of MWIR-LWIR dual-band imaging via StableSR-LoRA. (a) Schematic of the diffusion-based StableSR model with LoRA fine-tuning for infrared image enhancement. (b) Optimized MWIR imaging. (c) Optimized LWIR imaging.