The unprecedented ability of metallic subwavelength structures to confine and concentrate light into subwavelength spaces has led to new physics and exploration of novel devices. In this Letter, we demonstrate a 20 times enhancement of intersubband photoresponse in a InAs quantum dot (QD) system due to evanescently coupled plasmonic field. The resulting enhancement is accompanied by significant narrowing of photoresponse linewidth. The strong enhancement is attributed to efficient coupling of incident field to surface modes and to QDs, the presence of polarization-dependent absorption from QDs, and a fairly strong plasmon–QD interaction.
© 2014 Optical Society of America
Original Manuscript: April 21, 2014
Manuscript Accepted: June 19, 2014
Published: July 24, 2014
Rajeev V. Shenoi, Shawn-Yu Lin, Sanjay Krishna, and Danhong Huang, "Order-of-magnitude enhancement of intersubband photoresponse in a plasmonic quantum dot system," Opt. Lett. 39, 4454-4457 (2014)