Extremely Short Length and High Extinction Ratio Plasmonic TE Mode Pass Polarizer

Extremely short length and ultrahigh extinction ratio TE pass polarizer is proposed for wavelength 1.55μm. The polarizer section consists of an optical dielectric waveguide separated from the thin metal film plasmonic guide by a low index buffer layer. The thin film metal layer supports only Short Range Surface Plasmon Polariton (SRSPP) because effective indices below and above the metal film are different. Periodic coupling between the SRSPP mode and the optical waveguide mode takes place and varies with the length of the polarizer. It is shown that for a properly optimized metal and the buffer layer thicknesses, an extinction ratio of 223 dB can be achieved for a polarizer of length 4.6 μm. Dependence of polarizer length on the optimized buffer and metal layers is also discussed.