Detection of elliptical polarization characteristics using a metalens

Abstract

A metalens for detection a polarization ellipticity of an incident beam and the wavelength is considered in this work. The metalens is constructed of blocks of diffraction gratings with a height of 140 nm and a period of 220 nm. It works like a polarizer, which depends on one transverse coordinate, and a focuser. This metalens is capable of both separating linearly polarized radiation into two focal spots with circular polarizations of different signs, and detecting the direction and the ellipticity of the polarization. The metalens operates over a wide range of wavelengths from 0.55 to 0.837 μm, it can be used to estimate of the incident radiation wavelength in the range from 0.64 to 0.837 μm. This is possible due to the almost linear displacement of the focal spot in the transverse plane depending on the light wavelength.