Multi-functional gallium arsenide photonic crystal polarization splitter with a gold core

A multi-functional dual-core photonic crystal fiber (PCF) polarization beam splitter with a central oval hole filled with gold is designed and described. The first layer on the circular holes around the core is filled with the nematic liquid crystal (NLC) to enhance birefringence. The full-vector finite element method is employed to study the characteristics of the polarization beam splitter and derive the optimal parameters. When the fiber length is 14.55 μm, the polarized light in the x- and y-directions can be separated at a wavelength of 1.31 μm and the bandwidths are 257 and 238 nm, respectively, for extinction ratios bigger than 10 dB. When the fiber length is 10.86 μm, the polarized light in the x- and y-directions can be separated at a wavelength of 1.55 μm and the bandwidths are 239 and 174 nm, respectively for extinction ratios larger than 10 dB. The multifunctional polarization beam splitter with an ultra-short fiber length and broad bandwidth improves the sensing performance in comparison with single-function devices and our results provide insights into the design of beam splitters with multiple functions.