Wideband polarization-independent plasmonic switch based on GST phase-change material

Chalcogenide phase-change materials such as germanium-antimony-tellurium (GST) are suitable materials for use in tunable plasmonic devices. In this paper, a wideband plasmonic switch consists of gold cross-shaped resonators has been designed and simulated in the near-infrared region. The phase-change material GST makes the structure tunable, and by changing the temperature and switching between amorphous and crystalline states, the best extinction ratio of 14 dB and response time of 46 fs have been obtained at the wavelength of 1228 nm. The equivalent circuit model of the suggested structure has been extracted to verify the numerical results. Moreover, the effects of polarization and incident angles and geometric parameters on the structure performance have been evaluated. The proposed tunable and wideband switch with good switching capability can be used in various optical devices such as modulators, logic gates, and optical integrated circuits.