Efficient THz radiation source from spoof surface plasmons modes on a dielectric-filled metallic grating by electron beam

Abstract

Abstract Spoof surface plasmons(SSP) is attractive to develop efficient THz radiation source owing to its strong localized electric field. In this work, a THz radiation source based on SSP modes on a layered metal-dielectric plasmonic metamaterial is proposed and investigated. The dispersion characteristics of SSP modes on the structure are solved analytically and numerically. Besides, the propagation of SSP mode which is tuned by the filled dielectric is also demonstrated. Following the studies, THz radiation source which is induced by injected electron beam in the system is studied by a FDTD simulation method. The outputs of THz source based on the interaction between SSP mode and electron beam with various kinds of filled dielectric are given and compared with the same injected beam energy. It is shown that maximum power is decreased in the structure compared with no dielectric situation and the frequency spectrum is lowered. The presented studies about the excitation of SSP modes by electron beam on the structure may provide a good candidate of enhanced and tunable THz radiation source.