A TM-pass/TE-stop polarizer based on a surface plasmon resonance

Abstract

A TM-pass/TE-stop polarizer consisting of a metal film sandwiched between dielectric gratings is investigated using the finite-difference time-domain method. At normal incidence with respect to the grating plane, a transmissivity of more than 94 and a reflectivity of more than 98 are obtained at λ=1.55 m for the TM and TE waves, respectively. The extinction ratio is more than 17dB over a wavelength range of 1.50m to 1.75m. A high extinction ratio is maintained at oblique incidence, although the wavelength range shifts towards longer wavelengths. The TM-pass/TE-stop operation is also achieved with a modified structure, in which a dielectric grating is sandwiched between metal films.