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Title: Monolayer semiconductor nanocavity lasers with ultralow thresholds

Engineering the electromagnetic environment of a nanoscale light emitter by a photonic cavity can significantly enhance its spontaneous emission rate through cavity quantum electrodynamics in the Purcell regime. This effect can greatly reduce the lasing threshold of the emitter1–5, providing the ultimate low-threshold laser system with small footprint, low power consumption and ultrafast modulation. A state-of-the-art ultra-low threshold nanolaser has been successfully developed though embedding quantum dots into photonic crystal cavity (PhCC)6–8. However, several core challenges impede the practical applications of this architecture, including the random positions and compositional fluctuations of the dots7, extreme difficulty in current injection8, and lack of compatibility with electronic circuits7,8. Here, we report a new strategy to lase, where atomically thin crystalline semiconductor, i.e., a tungsten-diselenide (WSe2) monolayer, is nondestructively and deterministically introduced as a gain medium at the surface of a pre-fabricated PhCC. A new type of continuous-wave nanolaser operating in the visible regime is achieved with an optical pumping threshold as low as 27 nW at 130 K, similar to the value achieved in quantum dot PhCC lasers7. The key to the lasing action lies in the monolayer nature of the gain medium, which confines direct-gap excitons to within 1 nm of themore » PhCC surface. The surface-gain geometry allows unprecedented accessibilities to multi-functionalize the gain, enabling electrically pumped operation. Our scheme is scalable and compatible with integrated photonics for on-chip optical communication technologies.« less
Authors:
 [1] ;  [2] ;  [1] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [2] ;  [8] ;  [9]
  1. Univ. of Washington, Seattle, WA (United States). Dept. of Physics
  2. Stanford Univ., CA (United States). Ginzton Lab.
  3. Univ. of Washington, Seattle, WA (United States). Dept. of Physics; Tianjin Univ., Tianjin (China). Key Dept. of Applied Physics
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering
  5. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science & Technology Division; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering; Univ. of Tennessee, Knoxville, TN (United States). Dept. of Physics and Astronomy
  6. Humboldt Univ. of Berlin (Germany). Dept. of Physics
  7. Univ. of Hong Kong, Hong Kong (China). Dept. of Physics and Center of Theoretical and Computational Physics
  8. Univ. of Washington, Seattle, WA (United States). Dept. of Electrical Engineering
  9. Univ. of Washington, Seattle, WA (United States). Dept. of Physics; Univ. of Washington, Seattle, WA (United States). Dept. of Material Science and Engineering
Publication Date:
OSTI Identifier:
1265430
Grant/Contract Number:
AC05-00OR22725; FA9550-14-1-0277; EFRI-1433496; ECS-9731293; N00014-08-1-0561; FP7-ICT-2013-613024-GRASP
Type:
Accepted Manuscript
Journal Name:
Nature (London)
Additional Journal Information:
Journal Name: Nature (London); Journal Volume: 520; Journal Issue: 7545; Journal ID: ISSN 0028-0836
Publisher:
Nature Publishing Group
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
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