Independent control of birefringence and chromatic dispersion in a photonic crystal fiber using two hollow ring defects

We propose a new type of birefringent index guiding photonic crystal fiber (PCF) with two hollow GeO2-doped silica ring defects imbedded in a hexagonal hole arrays. Rigorous finite element method (FEM) using the perfectly matched layer (PML) was applied to calculate complex propagation constant and analyze optical transmission characteristics. Birefringence was flexibly controlled independent of chromatic dispersion, and improvement in confinement loss was achieved by optimizing hollow ring defect parameters.