High-Efficiency Full-Vector Polarization Analyzer Based on GaN Metasurface

The state of polarization (SOP) is the inherent property of light and has important applications in the field of electromagnetic waves, which can be usually evaluated by measuring the Stokes parameters. The conventional methods of measuring the SOP are based on numerous bulky devices and complex optical systems that make measurement difficult and cumbersome. Here, we propose an ultra-compact polarizer based on the gallium nitride metasurface in visible range, which consists of three parts to steer the four SOPs by utilizing double-phase modulation. X-, Y-, 45° linear polarized light and left circular polarized light can be simultaneously focused on spatially symmetric positions. The Stokes parameters can be immediately recovered through simultaneously measuring the focusing energy of the four polarizations. Our device shows reliable performance on polarization analysis as well as paves the way toward promoting the development of material analysis, chiral detections, and so on.