Nano-router metasurface inverse design by multi-body shape optimization.

Color image sensors that utilize Bayer filters are inherently limited by their narrowband optical filtering characteristics, which significantly reduce their optical efficiency. The emergence of metasurfaces functioning as nano-routers offers a promising alternative. However, the design, fabrication, and integration of nanophotonic structures into optoelectronic conversion sensors pose considerable challenges. In this study, we address these issues by employing a shape-optimization method to inversely design an RGGB optical nano-router based on a multi-body nanostructure, effectively balancing structural complexity and computational cost. Our results demonstrate that the designed nano-router achieves peak collection efficiencies of 53% for red, 70% for green, and 47% for blue. Notably, the metasurface's structural cross-section is composed solely of elliptical elements, rendering it highly compatible with mainstream fabrication techniques and facilitating easier integration.