Study on polarization properties of a novel high birefringence photonic crystal fiber

A novel kind of photonic crystal fiber (PCF) is proposed and investigated numerically by employing finite element method (FEM). This kind of PCF is composed of silica core and cladding with elliptical air holes of lozenge arrangement. The mode field distribution, effective refractive index, beating length and birefringence is studied. For comparative analysis, the properties of optimized hexagonal photonic crystal fiber with the same air holes size, shape, distance and layer number are also investigated. Simulation results demonstrate that the mode field of fundamental modes is restricted effectively in the core of the proposed PCF. High birefringence of the proposed PCF can be achieved easily as large as the order of 10^-2 at the wavelength of 1.55μm, which is higher than that of hexagonal PCF. A smaller beating length of the proposed PCF is also obtained at 1.55 μm. It is useful for a range of fiber optics sensing, communication in polarization-maintaining applications.