Calculation of photonic band-gap of one dimensional photonic crystal

Abstract

Photonic crystal is a composite dielectric with periodic modulation of refractive index that brings about unique photonic band-gap effect by which light could be totally reflected on the surface of such material regardless of any incident angle or mode. Many applications based on this mechanism have been developed and introduced into new waveguides. Such band-gap effect could be understood by investigating the optical performance of one dimensional photonic crystal. In this paper, the principle of band-gap effect of one dimension photonic crystal is firstly explained by Bragg reflection, the band-gap centre is obtained; then the modelling of band-gap of one dimension photonic crystal is conducted as well, the result is in agreement with the Bragg results and shows that the centre of photonic band-gap shifts to larger wavelength with higher refractive index (RI) ratio or dimension ratio between the two component dielectrics, but the involved boundary condition in simulation leads to higher onset RI ratio (3.5) responsible for the presence of photonic band-gap. This work would be useful to the design and fabrication of photonic crystal devices.