Linear polarization distinguishing metalens in visible wavelength.

A emerging optical metasurface has raised wide interest due to its planar structure and unprecedented control of light through subwavelength nano structures. In this study, we propose a novel metalens that integrates the function of a concentrating lens and linear polarizer. For this lens, focus can only be formed under the incidence of designed linear polarization, and its focusing effect is significantly suppressed upon the incidence of the orthogonal polarization. The linear polarization distinguishing focus characteristic is from the special design of anisotropic subwavelength phase shifters with two functionalities. One is the space-variant polarization distinguishing phase profile achieved through the engineering of a three-dimensional anisotropic phase shifter structure. The other is the selective generation of scattering loss on the incidence of its orthorgonal polarization. The linear polarization distinguishing metalens is fabricated through a complementary metal-oxide-semiconductor compatible nano fabrication process, and its performance is demonstrated through both simulation and experiment.