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Title: Terahertz graphene lasers: Injection versus optical pumping

We analyze the formation of nonequilibrium states in optically pumped graphene layers and in forward-biased graphene structures with lateral p-i-n junctions and consider the conditions of population inversion and lasing. The model used accounts for intraband and interband relaxation processes as well as deviation of the optical phonon system from equilibrium. As shown, optical pumping suffers from a significant heating of both the electron-hole plasma and the optical phonon system, which can suppress the formation of population inversion. In the graphene structures with p-i-n junction, the injected electrons and holes have relatively low energies, so that the effect of cooling can be rather pronounced, providing a significant advantage of the injection pumping in realization of graphene terahertz lasers.
Authors:
;  [1] ;  [2] ;  [3]
  1. Research Institute for Electrical Communication, Tohoku University, Sendai 980-8577 (Japan)
  2. Computational Nanoelectronics Laboratory, University of Aizu, Aizu-Wakamatsu 965-8580 (Japan)
  3. Department of Electrical Engineering, University at Buffalo, SUNY, Buffalo, New York 14260-1920 (United States)
Publication Date:
OSTI Identifier:
22261753
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1566; Journal Issue: 1; Conference: ICPS 2012: 31. international conference on the physics of semiconductors, Zurich (Switzerland), 29 Jul - 3 Aug 2012; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ELECTRONS; GRAPHENE; LASERS; OPTICAL PUMPING; PHONONS; POPULATION INVERSION; SEMICONDUCTOR JUNCTIONS; SOLID-STATE PLASMA