Tunable transmission near Dirac-like point in the designed plasma photonic crystal

The ingenious combination of gaseous plasma and alumina columns forms a plasma photonic crystal with the advantage of dynamic tunability to control the transmission of electromagnetic waves. Plasma density as another degree of freedom is used to realize the Dirac-like cone, which degenerates accidentally at the first Brillouin zone in a square lattice. The investigations of transmission spectrum and phase variation demonstrate that the Dirac-like cone formed in a plasma photonic crystal still possess the zero-refractive-index property, and the cloaking effect for obstacles can be turned on or off by adjusting the electron density. Based on the feature of dynamic tunability, the dual-channel optical switch is designed, and the transmission path of electromagnetic waves can be controlled dynamically.