Elliptical Photonic Crystal Fiber Polarization Filter Combined With Surface Plasmon Resonance

Abstract

An elliptical photonic crystal fiber (PCF) polarization filter based on surface plasmon resonance is proposed. Two smaller elliptical air-holes are selectively filled with gold wires to improve the filter characteristics by the surface plasmon effect. The transmission characteristics and influence of structural parameters are analyzed by the finite-element method. Research shows that the loss of y-polarization is much greater than that of x-polarization. The air holes filled with gold have the greatest influence on the loss of PCF, and the air holes around the fiber core have the greatest effect on the dispersion. In the optimized model, the loss of y-polarization is 333.84 dB/cm, but the loss of x-polarization is only 1.5 dB/cm at 1.55 $\mu \text{m}$ . Besides, when the length fiber is $L= 3$ mm, the extinction ratio is 866 dB, and the bandwidth can reach 500 nm, which embodies high extinction ratio and wide bandwidth of this filter.