Omnidirectional transparency induced by matched impedance in disordered metamaterials

Abstract

In this work, we present an omnidirectional perfect transmission in the photonic band gap of a metamaterial, where positive-index and active negative-index materials are randomly stacked. Due to mismatched impedance, a photonic band gap appears when the metamaterial possesses zero averaged refractive index. By introducing the matched impedance at the expected frequency, a complete tunneling is achieved in the photonic band gap. This kind of transparency is robust against not only incident angles, optical polarization but system disorder as well. The finding is expected to achieve potential applications in optoelectronic devices.