Surface plasmon resonance effect induced tunable polarization filter based on gold film selectively coated photonic crystal fiber

A polarization filter based on photonic crystal fiber selectively coated with gold film is investigated. The loss spectra and the dispersion characteristics of the designed polarization filter are studied and analyzed by the finite element method. Simulation results show that the loss of core mode is 433.65 dB/cm in y polarization and 2.64 dB/cm in x polarization at the wavelength of 1.55 µm, respectively. The bandwidth of extinction ratio greater than −20 dB is 150 nm. The corresponding wavelength range is from 1.48 µm to 1.63 µm. The position and size of the little air holes along with the thickness of gold film showed influence on the polarization filter properties. And the proposed polarization filter has stable properties of with difference size and position of the little air holes. The designed polarization filter showing excellent properties can be used in polarizations filter in communication transmission.