Air-like plasma frequency in one-dimensional plasma photonic crystals

Abstract

A one-dimensional plasma photonic crystal, which consists of periodically alternating layers of quartz discharge tubes and air, is proved to have a special photonic bandgap. It is found that in the absence of plasma, the quartz tube array can give rise to a bandgap within a fixed frequency band. Interestingly, both effective medium theory and experimental results reveal that such a bandgap can be closed in the existence of the plasma with an appropriate plasma density and can be reopened as the increase in the plasma density. The unique behavior of the bandgap also depends on the collision frequency of the plasma. To describe these phenomena, an air-like plasma frequency is defined. These studies pave the way for realizing tunable bandgaps in microwave applications.