Turning photonic band gap of one-dimensional photonic crystals on and off

Abstract

Abstract A one-dimensional photonic crystal consisting of alternating layers of a sandwich structure and air is proposed to obtain a photonic band gap (PBG) that can be completely closed or opened. Through theoretical calculation and numerical simulation, we prove that the mechanism of controlling the gap is closely related to the impedance of the sandwich structure. Simply put, if the frequency at the middle of a gap makes the effective impedance of the sandwich be equal to 1, this gap will close. By introducing plasma into the sandwich, we can turn the PBG on or off conveniently. These studies pave the way for realizing tunable microwave application, such as optical signal switches.