Broadband omnidirectional near-infrared reflector based on an angle-insensitive photonic band gap.

Abstract

Owing to the Bragg interference mechanism, band gap in all-dielectric one-dimensional photonic crystal (1DPC) is strongly sensitive to the incident angle, which limits the width of omnidirectional band gap. Based on the angle-insensitive Bragg band gap in 1DPC composed of alternating dielectric and hyperbolic metamaterial layers, we design a broadband omnidirectional near-infrared mirror with the bandwidth of 943 nm (52.3% relative bandwidth) without using the conventional cascade method. In addition, we show that the angle-insensitive property of the band gap is robust against the layer thickness disturbance. This multilayer-based broadband omnidirectional reflector will possess potential applications for omnidirectional filters within broad stopbands and photonic crystal fibers with broad operating bandwidths.