Design of polarization beam splitter based on dual-core photonic crystal fiber with three layers of elliptical air holes

A polarization beam splitter (PBS) based on dual-core photonic crystal fiber (DC-PCF) with three layers of elliptical air holes is proposed. The full-vector finite element method is used to investigate the coupling and propagation characteristics of the PBS, and the three-dimensional beam propagation method is used to demonstrate the evolutions of the x-pol and y-pol light fields in cores A and B of the DC-PCF. In this design, the elliptical air holes are introduced to enhance the birefringence of the DC-PCF. The simulation results show that, with the proposed PBS, the complete beam splitting can be achieved at wavelength 1.55 μm when the fiber length is 254 μm. Moreover, when the extinction ratio is less than −20 dB, the bandwidth of the PBS can be up to 48 nm, covering the whole C-band. It is believed that the proposed PBS will be a promising candidate in laser and sensor systems.