Development of a Full-Color Metalens for Near-Diffraction-Limited Focusing Performance

We designed, fabricated, and characterized a full-color metalens using cross-shaped meta-atoms made of SiN. By controlling the phase distribution at three wavelengths (450 nm, 532 nm, and 633 nm) independently, we aimed to correct chromatic aberration and achieve a constant focal length for all three. By introducing correction terms to phase profiles for each wavelength, we demonstrated high focus performance through simulations. In the evaluation, we confirmed that the fabricated metalens successfully focused all three wavelengths, with the focal distance error within ±1%.