Surface plasmons based transmission enhancement of terahertz through metal aperture arrays

摘要

Extraordinary transmission spectrum of a copper film pierced with a periodic array of subwavelength rectangular holes is measured by the terahertz time-domain spectroscopy. The transmission coefficient is strongly depended on the angle between the polarization of terahertz electric field and the latitudinal direction of the periodic apertures. When the angle increases from 0° to 90°, a transmission peak becomes stronger and another peak reduces. The transmission is proposed to be the contributions of the localized surface plasmons inside the apertures. The finite-difference-time-domain (FDTD) simulation results are in good agreements with the experimental observations.