Band structure for the cladding of a hollow core photonic crystal fibre

Abstract

We calculate the photonic band structure of a two dimensional (2D) photonic crystal (PC) formed by a hexagonal array of circular rings embedded in air. This crystal has been used as the cladding of a photonic crystal fibre whose core is composed of air. We solve the Maxwell equations using the plane wave method to expand the fields and the dielectric constant. Our calculations reveal that for propagation in the plane of periodicity, the PC possesses no complete photonic band gaps. However we demonstrate the existence of complete photonic band gaps for propagation out of the plane of periodicity.