Generation of Optical Vortex Array by the Quasi-Talbot Effect With All-Dielectric Metasurface

In this letter, we numerically and experimentally demonstrate the highly efficient generation of optical vortex arrays based on the quasi-Talbot effect with a reflective all-dielectric metasurface, which is composed of six identical orbital angular momentum lenses. Six separated and focused optical vortices at the focal plane can be high efficiently generated, and form a vortex array at the defocusing plane through the quasi-Talbot effect. The proposed metasurface is made from a commercial silicon on insulator wafer with a high integrated level, which enables the integration of our approach in on-chip platforms for optical lithography and manipulation applications.