Aberration-corrected wide wavelength range spectrum dispersion element based on the Pancharatnam-Berry metasurface

Abstract

As a typical type of metasurface, the Pancharatnam-Berry (PB) phase metasurface can enable the miniaturization of a spectrometer because of its sub-wavelength and ultra-thin properties. We proposed what we believe to be a novel miniaturized metalens with multiple aberrations as a dispersive element based on the Gaussian reference sphere theory. The metalens was combined with different focal points and designed wavelengths to reduce aberrations over a broadband range. Compared with lenses with spherical or parabolic phase profiles, the proposed phase profile PB metasurface achieved focal lengths corresponding to the incident light of different wavelengths in a larger range, resulting in a higher spectral resolution rate and suitability for diverse spectrometer applications. Compared with spherical or parabolic phase distribution, the PB metasurface based on segmented phase distribution achieved focal lengths corresponding to the incident light of different wavelengths in a larger range; aberration correction could be performed in a wider wavelength range. When implemented within the system, the spectrometer can use higher spectral resolution and a wider wavelength range. The detailed design method and theoretical spectrum dispersion ability were analyzed. The proposed metasurface provides a new method for designing dispersion devices with high spectral resolution and has potential applications in the fields of spectrometry, three-dimensional imaging, and portable optics.