Polarization-stable highly birefringent photonic crystal fiber with near-elliptic inner cladding structure

Abstract

A new near-elliptic inner cladding (NEIC) structure of polarization-stable highly birefringent photonic crystal fiber (HB-PCF) is proposed and analyzed by using a full-vector finite element method (FEM) with anisotropic perfectly matched layers. From the numerical results it is confirmed that, with the diameter of air hole A varied by ~10%, the modal birefringence degradations of the three proposed NEIC-PCFs are less than 4.2 × 10^-5, 6 × 10^-5 and 1.17 × 10^-4, respectively, while the average birefringence is of the order of 2 × 10^-3 at 1.55μm, which strongly proves that the proposed structure is highly polarization-stable. Especially, the MFDs in x-direction and y-direction of NEIC-PCF with three holes diminished in the center are measured as 5.8 μm and 2.6 μm, respectively, which are very attractive in the application field of fiber optic sensor, e.g. fiber optic gyros.