Superluminal propagation of surface waves in one-dimensional magnetized plasma-ferrite crystals

The dispersion characteristics of surface waves in a novel one-dimensional (1D) magnetized plasma-ferrite photonic crystal are investigated using the transfer matrix method (TMM) and Maxwell’s equations, both theoretically and analytically. A wide photonic bandgap with a very narrow pass band is observed when the structure is composed of periodically stacked layers of magnetized plasma and magnetized ferrite. It is also observed that bandgap’s characteristics can be manipulated by varying structural parameters such as filling factor, plasma frequency, and external magnetic field. The key finding of this study is the anomalous dispersion. Due to this behavior, the electromagnetic (EM) waves propagate with superluminal or negative group velocity, suggesting that the EM wave appears to exit the medium before entering it. Theoretical computations of the phase index, group velocity, and anomalous dispersion also adequately explain the fast light effect. The result obtained can be harnessed in the fields of ultrafast photonics, optical frequency filters, optical communication, biosensing applications, and optical delay lines.