LAUSR

We propose two mid-infrared photonic crystal fibers with an elliptical As 2 S 3 core and a dual-cladding structure with high birefringence and high nonlinearity. The cladding filling material is silica and the core material is As 2 S 3 . The full vector finite-element method is used to study the birefringence, and nonlinear coefficient of the structure in the 3–5 μm band. The Simulation results show that the birefringence of the two structures can reach a maximum of 0.2169, and the nonlinear coefficient can reach a maximum of 3763.42 W −1 /km. From these characteristics, it is concluded that the proposed structure will be ideal for mid-infrared fiber sensing, precision optics and nonlinear optics.