Design of broadband single-polarization filter based on simple structure photonic crystal fiber with gold-coated air holes

A polarization filter based on simple structure photonic crystal fiber (PCF) coated with gold air holes is designed in this work. The full vector finite element method (FEM) is used to calculate the characteristic parameters of PCF. In the final numerical simulation results, the loss peak in the [Formula: see text] polarization direction is 2305.72 dB/cm and the [Formula: see text]-polarized loss is as low as 75.86 dB/cm at 1.31 [Formula: see text]m. For the fiber length of 1000 [Formula: see text]m, the CT reaches 1936.83 dB and a wide bandwidth greater than 20 dB can provide above 800 nm. The content of this paper can provide a new idea for filter structure design.