Simplest but Efficient Design of a Color Router Optimized by Genetic Algorithms

We demonstrated a simple and efficient metasurface color router for CIS with an RGGB Bayer layout requiring only a single nanopillar for each pixel. Each nanopillar directionally scatters light, redirecting unwanted light into neighboring pixels and achieving over 100% efficiency. Using genetic algorithms, we optimized the nanopillar dimensions to maximize router efficiency. For measurement, we initially designed a metasurface color router for light incident from the substrate, allowing us to assess its optical properties in the air. Compared to the ideal efficiency without a color router, our structure presented enhanced efficiencies of 152%, 180%, and 120% at 633, 532, and 480 nm, respectively. Finally, we proposed a practical design for practical application conditions where the incident light propagates from air to the color router.