Switching characteristics of periodically multilayered gyromagnetic metamaterials in waveguide structure

This article utilizes the waveguide structure and theory to analyze the electromagnetic wave propagating in periodically multilayered gyromagnetic metamaterials (PMGMs) with the control of external static magnetic field. Based on this, the reflection and transmission characteristics of the PMGMs terahertz (THz) optical switch are further explored. The switchable characteristics shown by the dispersion curves of transverse electric (TE) modes in the three-layered planar gyromagnetic metamaterial waveguides (GMMWs) are analyzed in detail. The numerical results demonstrate that the dispersion curves of GMMWs appear an adjustable bandgap under the external static magnetic field tuning. Furthermore, the full transmission phenomenon appears when the PMGMs THz optical switch presents an ON state, by adjusting the filling ratio and external static magnetic field. The mechanism is analyzed. These properties make it possible for PMGMs to be widely used in the design of photoswitch, phase modulator and so on.