Polarization filter characteristics of photonic crystal fibers with square lattice and selectively filled gold wires.

A novel design of Au-filled photonic crystal fiber (PCF) with square lattice has been proposed in this paper. The resonance strength of the surface plasmon mode and the impacts of structural parameters of the PCF on the polarization filter characteristics are studied through the finite element method. Numerical results show that the sizes of Au wires and the symmetry of the air holes near the fiber core have a great effect on the polarization filter characteristics. In the optimization process, it was found that the resonance strengths can reach 279.10 and 399.18 dB/cm at wavelengths of 1.02 µm and 1.55 µm, respectively, which can be applied in many polarization filter devices.