Hight efficient waveplates and microlens arrays designed by metasurface

Abstract

Metasurface has gained increasing research attention due to their remarkable abilities in light manipulation, versatility, ease of on-chip fabrication and integration owing to their planar profiles. In this talk, we will introduce our recent progress on this subject by focusing on two novel applications: one is for waveplates (polarization manipulation) and the other is for compact lenses. An ultrathin, broadband half-wave plate in the near-infrared range using a plasmonic metasurface will be first presented [1]. The simulated results show that the linear polarization conversion efficiency is over 97% with over 90% reflectance across an 800-nm bandwidth, which was experimentally verified over a wide range of incident angles. A plate with supercell design was also realized to achieve reflection-phase gradient for the cross-polarized beam that could separate the anomalous (cross-polarized) and the normal (co-polarized) reflected beams. In the second part, a metasurface lens made of silicon rod arrays will be presented with transitivity larger than 80% at the light communication wavelength. We will mainly discuss its application potential in microlens array. In addition, we will also talk how to design metasurface lens that could deal with evanescent waves [2].