Extended depth of focus metalens toward the entire long-wave infrared spectrum through inverse design framework.

Abstract

We present an inverse design framework for long-wave infrared (LWIR) extended depth of focus (EDOF) metalenses, integrating angular spectrum theory and genetic algorithm optimization with phase encoding. This approach achieves a 7.2× depth of field (DOF) enhancement and near-diffraction-limited performance compared to conventional metalenses. By balancing EDOF functionality and broadband operation, the optimized metalens maintains imaging fidelity with 65% confocal overlap across the LWIR spectrum, featuring spatially consistent point spread functions (PSFs) and uniform focal spot distributions. This work establishes a scalable methodology for multifunctional metasurface engineering, offering transformative potential for advanced LWIR imaging systems.