Nanostructured Photonic Crystal Fiber with Ultra-high Birefringence

A nanostructured photonic crystal fiber (PCF) with elliptical air holes in the fiber core is proposed. Both ultra-high birefringence and ultra-low confinement loss can be achieved simultaneously in a large wavelength region for a PCF with only four rings of arrays of circular air holes in the fiber cladding. Uniform and ultra-high birefringence can be achieved by employing elliptical air holes both in the fiber cladding and fiber core. The proposed method by employing nanostructured air holes in the fiber core is also expected to optimize other characteristics (such as dispersion) of the PCF.