Electronically tunable extraordinary optical transmission in graphene plasmonic ribbons coupled to subwavelength metallic slit arrays

• Published in: Nature communications Vol. 7; no. 1; p. 12323
• Main Authors: Kim, Seyoon, Jang, Min Seok, Brar, Victor W., Tolstova, Yulia, Mauser, Kelly W., Atwater, Harry A.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 08.08.2016; Nature Publishing Group; Nature Portfolio
• Subjects: 132/122; 140/133; 142/126; 639/301/1019/1021; 639/624/399/918/1054; 639/624/400/1021; Arrays; Geometry; Graphene; Humanities and Social Sciences; Light; MATERIALS SCIENCE; multidisciplinary; Science; Science (multidisciplinary); Simulation; United States > US; California
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms12323

Subwavelength metallic slit arrays have been shown to exhibit extraordinary optical transmission, whereby tunnelling surface plasmonic waves constructively interfere to create large forward light propagation. The intricate balancing needed for this interference to occur allows for resonant transmission to be highly sensitive to changes in the environment. Here we demonstrate that extraordinary optical transmission resonance can be coupled to electrostatically tunable graphene plasmonic ribbons to create electrostatic modulation of mid-infrared light. Absorption in graphene plasmonic ribbons situated inside metallic slits can efficiently block the coupling channel for resonant transmission, leading to a suppression of transmission. Full-wave simulations predict a transmission modulation of 95.7% via this mechanism. Experimental measurements reveal a modulation efficiency of 28.6% in transmission at 1,397 cm −1 , corresponding to a 2.67-fold improvement over transmission without a metallic slit array. This work paves the way for enhancing light modulation in graphene plasmonics by employing noble metal plasmonic structures. Graphene-plasmon optical modulators with broadly tunable operating frequencies are sought for photonic applications. Here, Kim et al. demonstrate tunable mid-infrared transmission that utilizes resonant absorption in graphene ribbons to modulate the extraordinary optical transmission effect in metallic slit arrays.