Polarization-controlled dynamically switchable plasmon-induced transparency in plasmonic metamaterial.

Dynamical manipulation of plasmon-induced transparency (PIT) in metamaterials promises numerous potential applications; however, previously reported approaches require complex metamaterial structures or an external stimulus, and dynamic control is limited to a single PIT transparency window. We propose here a metamaterial with a simple structure to realize a dynamically controllable PIT effect. Simply by changing the polarization direction of incident light, the number of PIT transparency windows can be increased from 1 to 2, accompanied by a tunable amplitude and a switchable resonance-wavelength. Moreover, a coupled three-level plasmonic system is employed to explain the underlying mechanism and near-field coupling between the horizontal and vertical gold bars, and the analytical results show good consistency with the numerical calculations. This work provides a simple approach for designing compact and tunable PIT devices and has potential applications in selective filtering, plasmonic switching and optical sensing.