Octagonal photonic crystal fiber dual core polarization splitter

Abstract

An octagonal dual core polarization splitter based on highly birefringent photonic crystal fiber (PCF) is proposed and the full vector finite element method (FEM) is employed to analyze the impacts of structural parameters on birefringence and the coupling length, and simulation results show that high birefringence on the order of 10−3 can be achieved at 1.55μm, moreover, the hole size and hole pitch both affect birefringence and the coupling length. Based on these results, the PCF's structure is optimized to realize a polarization splitter of 314μm whose largest extinction ratio is around −50.5dB at 1.55μm. Meanwhile, the bandwidth at the extinction ratio of −10dB is about 170nm, and around 60nm at −20dB.