Design of wire-grid polarizer with effective medium theory

A design concept of a wire-grid polarizer, which is based on the effective-medium theory, has been proposed. The effective indices of a wire-grid grating are evaluated with the effective-medium theory. The results show that, the wire-grid grating acts as a metal for TE polarization, but it behaves like a dielectric material for TM polarization. According to the different effective optical properties of the wire-grid grating for the different polarizations, a wire-grid polarizer with a high polarization ratio can be obtained by enhancing both the transmission for TM polarization and the reflection for TE polarization.