Design of Photonic Crystal Fiber Polarization Filter Based on Surface Plasmon Resonance

Compared to the traditional optical fibers, photonic crystal fibers have the characteristics of no cut-off single-mode transmission, high birefringence and low refractive index air holes. The performance of photonic crystal fibers can be further enhanced and flexibly expanded by filling metal, liquid crystal or other materials. In this paper, a novel photonic crystal fiber polarization filter is proposed. The finite element method is used to numerically study the gold and silver symmetrically coated photonic crystal fiber polarization filter. Silver layers coated around the air holes in the horizontal direction of the core are used to motivate surface plasmon resonance (SPR) with x-polarized core mode and gold layers coated covered around the air holes in the vertical direction of the core are used to excite the SPR with y-polarized core mode. Due to the different resonance wavelength of x/y polarized core mode in the loss spectra, x/y polarized light can be filtered in different wavelength.