Design of an ultrashort single-polarization wavelength splitter based on gold-filled square-lattice photonic crystal fiber

A compact gold-filled square lattice PCF is proposed and analyzed by the finite element method, being capable of wavelength splitting the incoming light at wavelength bands of 1.31 and 1.55 μm with two orthogonal polarization states. The reported PCF based wavelength splitter can achieve 373.79 dB/cm resonance losses for y -polarized core mode at communication wavelength of 1.31 μm with low loss of 9.41 dB/cm for x -polarized core mode. Moreover, resonance loss of 214.31 dB/cm can also be achieved for x -polarized core mode at communication wavelength of 1.55 μm with low loss of 3.88 dB/cm for y -polarized core mode. Additionally, the proposed wavelength splitter possesses an ultrashort length of 0.3 mm with bandwidths of 40 and 165 nm around the wavelengths of 1.31 and 1.55 μm, respectively.