Near-infrared orthogonal polarized metalens

A metalens is a planar optical device that can accurately control the phase, polarization, and amplitude of light. Aiming at the application requirements of polarization imaging equipment for miniaturization, integration, and common field of view, we designed and fabricated two kinds of orthogonally polarized metalenses based on amorphous silicon and fused quartz. These metalenses can achieve orthogonal linear or circular polarization light imaging with a common field of view. The samples with a 2-mm diameter and 20-mm focal length were fabricated by electron beam exposure. The test results show that these metalenses can realize the imaging of orthogonal linearly or circularly polarized light simultaneously; the focusing efficiency is more than 50%, and the polarization contrast is >22 dB.