A novel Ge20Sb15Se65 based photonic crystal fiber (PCF) with all circular air holes distributed in simple square lattice geometry is proposed which exhibits ultra-high birefringence and large nonlinearity. Different optical properties are investigated in mid infrared range by using finite-element method (FEM). Simulation results show that by optimizing the cladding arrangement the proposed PCF offers high birefringence of 0.2978, large nonlinearity of 6585 W−1 km−1. Moreover, zero dispersion can be obtained at 3.9 μm for x mode and 4.95 μm for y mode with nonlinearity of the order of 103 W−1 km−1 which also can be tailored by adjusting the cladding air hole diameter. This proposed PCF can be utilized for mid infrared supercontinuum generation, fiber sensor, and spectroscopy systems.