Arrays of subwavelength dipole bow-tie apertures are designed and characterized at terahertz frequencies. For an incident terahertz field perpendicular to the longer axis of the bow tie, a strong resonance enhancement, line narrowing, and a nonmonotonic frequency shift were observed with increasing length of the tapered bow-tie arms. Such characteristic behaviors primarily originate from localized surface plasmon resonances. In addition, with a decreasing aperture size, the contribution of localized plasmons becomes prominent due to an increase in plasmonic lifetime as the terahertz pulses strongly couple with the metallic surface surrounding the bow-tie apertures.
© 2011 Optical Society of America
Original Manuscript: March 30, 2011
Revised Manuscript: June 8, 2011
Manuscript Accepted: June 12, 2011
Published: July 28, 2011
Yuping Yang, Ranjan Singh, and Weili Zhang, "Anomalous terahertz transmission in bow-tie plasmonic antenna apertures," Opt. Lett. 36, 2901-2903 (2011)