Single-polarization photonic crystal fiber filter composed of elliptical gold films

A metallic photonic crystal fiber (PCF) filter based on surface plasmon resonance is designed and investigated by the full-vector finite-element method. The inner wall of the air holes in the PCF is coated with gold layers of different thicknesses. The x-polarized and y-polarized confinement losses of the core mode are as high as 1920.36 dB / cm and as low as 3.29 dB / cm at 1310 nm, respectively. For a fiber length of 1000 μm, the crosstalk of the filter is 1665.14 dB at 1310 nm and the available optical bandwidth is 779 nm. The results show that the PCF filter has excellent prospect in optical information processing.