Highly birefringent elliptical-hole rectangular-lattice photonic crystal fibers with modified air holes near the core

Abstract

In this work, modal birefringence and polarization-dependent leakage loss for the fundamental mode in elliptical-hole rectangular-lattice photonic crystal fibers (EH-RL-PCFs) with modified air holes near the core are investigated by using a full-vector, finite-difference method in the frequency domain. Numerical results show that by introducing modified air holes, a heightened modal birefringence of the order of 10(-2) has been obtained within the wavelengths ranging from 1.0 to 1.6 mum in the proposed PCFs, with a lattice length of 2 mum and with a large lattice length of 3 mum at1.55 mum.