Polarization splitter based on highly birefringent dual-core photonic crystal fibers

Based on the birefringence effect, a novel duel-core photonic crystal fiber polarization beam splitter was proposed. The birefringence of the splitter was improved by introducing dual elliptical air holes into each fiber core of the rectangle lattice structure photonic crystal fiber. Using the full-vector finite element method (FEM), the impacts of structural parameters of duel-core photonic crystal fiber on birefringence and coupling length were analyzed. And the characteristics of the splitter, such as coupling length, extinction ratio and bandwidth, were investigated. Numerical simulation results demonstrate that the coupling length is decreased while the birefringence is increased by increasing the ellipticity, and the isolation of the polarization state can be achieved and the polarized light extinction ratio is-45.42 dB when the working wavelength and transfer-length of the fiber are 1.55 m and 282 m, respectively. Besides, the extinction ratio is less than-10 dB when the bandwidth is 89 nm as well as the range of the wavelength is 1.507-1.596 m.