Design and analysis of polarization splitter based on dual-core photonic crystal fiber

We propose a novel structure of polarization splitter based on symmetric dual-core PCF with triangular lattice. The polarization-dependent coupling properties for x and y polarization modes, including coupling length, coupling length ratio (CLR) and propagation process in the designed splitter, are numerically investigated by using the full-vector finite element method (FEM) and the semi-vector beam propagation method (BPM). The simulation results show that CLR can be tuned to be about 4/3 and 3/2 at lambda = 1.55 mu m to meet the requirement of polarization split by optimizing the geometric parameters. For the case of CLR = 4/3, the polarization splitter with a total physical length of 3.12 mm is obtained and its extinction ratio is as low as -48 dB at lambda = 1.55 mu m.