A novel high birefringence photonic crystal fiber with squeezed elliptical holes

A novel high birefringence photonic crystal fiber (PCF) is proposed in this work. This PCF is composed of a solid silica core and a cladding with elliptical air holes and squeezed triangular lattice. The high birefringence is introduced on the combined effect of elliptical air holes, the squeezed lattice and the air holes of two sizes in cladding. Our numerical results based on the supercell lattice method indicate that the birefringence can reach as high as 0.0019 at 1.55μm wavelength with a properly designed cladding structure. We also analyze the dependence of the birefringence on structure parameters.