Multifunctional LWIR metalens integrating polarimetric detection, bright-field imaging, and edge enhancement.

The trend toward miniaturization and integration in imaging systems has significantly advanced the development of metasurface technology. The application of metalens technology in the long-wave infrared (LWIR) band demonstrates significant potential and distinct advantages. We propose an LWIR metalens capable of polarimetric detection, edge enhancement, and bright-field imaging. Extracting target contours in complex environments enables high-precision intelligent recognition and detection. An interleaved metasurface structure spatially separates the six focal spots generated under three orthogonal polarization states allowing single-shot acquisition of Stokes parameters for polarimetric detection. Edge enhancement is implemented by introducing a vortex phase at one focal spot, while the other five spots perform Gaussian focusing for bright-field imaging. Based on this multifunctional integration, two metalenses with different focal lengths are designed using shared and separate focal planes. The simulated sidelobe ratios under vortex focusing reach -13.3 dB (confocal) and -11.6 dB (spatially segregated focal), indicating strong energy confinement and effective sidelobe suppression. This work holds promising application value in areas such as military reconnaissance, atmospheric remote sensing, geophysical exploration, damage assessment, and medical diagnostics.