Asymmetric multichannel spin-dependent splitting based on a single-layer dielectric metasurface

Abstract

Realization of multichannel spin-dependent splitting that allows for wavefront shaping is urgently required in applications based on the photonic spin Hall effect (PSHE). In this paper, we implement the multichannel spin-dependent splitting that supports preset laser modes by using a single-layer dielectric metasurface. This metasurface introduces a dynamic phase and a Pancharatnam-Berry phase simultaneously, which allows for encoding two independent phase distributions to the two orthogonal circular polarizations. We demonstrate that in the proposed multichannel spin-dependent splitting, the intensities of the beams, the locations of the spots, and the number of the spin-dependent channels, can be asymmetric. Consistent results given by the Fresnel diffraction integral formula and the finite difference time domain method reveal the good performance of the implemented multichannel spin-dependent splitting. This paper offers a simple and convenient approach to manipulate spin photons, which may serve the PSHE-based applications in optical information processing, precision metrology, and edge imaging.