Efficient photonic crystal fiber polarization splitters composed of gallium arsenide and nematic liquid crystals

Two photonic crystal fiber (PCF) polarization beam splitters (PBSs) featuring ultra-short length and ultra-high extinction ratios at wavelengths of 1.31 μm and 1.55 μm are designed and investigated. Non-silicon materials, such as gallium arsenide (GaAs) and nematic liquid crystal (NLC), are incorporated into the structure to ensure operation of the splitters in the communication bandwidth. Based on the full-vector finite element method (FEM), numerical simulation is carried out to optimize the structural parameters systematically. Specifically, for the splitter operating at 1.31 μm, the optimal optical fiber length, extinction ratio, and bandwidth are 27.87234 μm, -152.40 dB, and 152 nm, respectively. In comparison, the optimal fiber length, extinction ratio, and bandwidth of the splitter at the wavelength of 1.55 μm are 15.59356 μm, -137.21 dB, and 200 nm, respectively. The results reveal that the splitters have great potential in environmental monitoring, biochemical detection, and optical communication.