Plasmonic terahertz lasing in an array of graphene nanocavities

V. V. Popov,1,2,* O. V. Polischuk,1,2 A. R. Davoyan,1 V. Ryzhii,3 T. Otsuji,3 and M. S. Shur4 1Kotelnikov Institute of Radio Engineering and Electronics (Saratov Branch), Russian Academy of Sciences, Saratov 410019, Russia 2Saratov State University, Saratov 410012, Russia 3Research Institute for Electrical Communication, Tohoku University, Sendai 980-8577, Japan 4Department of Electrical, Computer, and Systems Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA (Received 27 July 2012; revised manuscript received 31 October 2012; published 30 November 2012)