A Metalens for Evaluation of a Polarization Ellipticity

In this study, a numerical investigation of a metalens for determination of an incident light field polarization ellipticity was carried out using finite-difference time-domain (FDTD) simulations. The proposed metalens is formed by units of diffraction gratings with a period of 0.22 μm and a height of 0.14 μm. The presented lens simultaniosly focuses light and performes as a polarizer, which contingents upon one transverse coordinate. It is able to separate incident linearly polarized light into two focal spots with circular polarizations of opposite signs, and at the same time determine the polarization ellipticity and direction. The working range of the developed metalens is quite wide and includes wavelengths from 0.55 to 0.837 μm.