Experimental Demonstration of Spoof Surface Plasmon Based THz Antennas for Huge Electric Field Enhancement

Abstract

We experimentally demonstrate the fabrication and optical measurement of a novel terahertz antenna array due to the excitation of spoof surface plasmon modes. With the unit cell composed of ultrathin copper film corrugated with three rectangular grooves, the designed plasmonic antenna array fabricated on the quartz substrate clearly shows multiple plasmonic resonances, including the regular broadband dipolar-like and sharp Fano resonances. Terahertz time-domain measurements were performed and the transmission spectrum shows quite good agreement with full wave numerical simulations. These results provide direct evidence for the validity of the novel antenna design, which is expected to exhibit huge local field enhancement suggesting highly potential applications in terahertz sensing and detections.