Tunable polarization splitter based on asymmetric dual-core liquid photonic crystal fiber

Abstract

Tunable photonic crystal fiber polarization splitter is proposed and analyzed. The proposed splitter has a dual asymmetric cores where one core is only filled with a nematic liquid crystal (NLC). The birefringence is also increased between the two polarized modes due to the NLC material which improves the splitting performance. The coupling between the two asymmetric cores occurs at a specific wavelength which can be controlled by the NLC material. Additionally, the splitting between the two polarized modes can be tuned by rotating the NLC molecules using an external electric field. Further, the matching wavelength where the power coupling occurs between the two asymmetric cores can be controlled thermally due to the NLC dependence on the temperature. The analysis of the proposed splitter is carried out using full vectorial finite difference method. The reported polarization splitter has a compact device length of 602 µm at λ = 1.3 μm with high wavelength selectivity. In addition, large bandwidth of 60 nm is obtained with crosstalk lower than − 20 dB which ensures the superiority of the reported device.