Journal of Infrared, Millimeter, and Terahertz Waves

, Volume 32, Issue 5, pp 655–665

Observation of Amplified Stimulated Terahertz Emission from Optically Pumped Heteroepitaxial Graphene-on-Silicon Materials

Authors

  • Hiromi Karasawa
    • Research Institute of Electrical CommunicationTohoku University
  • Tsuneyoshi Komori
    • Research Institute of Electrical CommunicationTohoku University
  • Takayuki Watanabe
    • Research Institute of Electrical CommunicationTohoku University
  • Akira Satou
    • Research Institute of Electrical CommunicationTohoku University
    • JST-CREST
  • Hirokazu Fukidome
    • Research Institute of Electrical CommunicationTohoku University
    • JST-CREST
  • Maki Suemitsu
    • Research Institute of Electrical CommunicationTohoku University
    • JST-CREST
  • Victor Ryzhii
    • Depertment of Computer Science and EngineeringUniversity of Aizu
    • JST-CREST
    • Research Institute of Electrical CommunicationTohoku University
    • JST-CREST
Article

DOI: 10.1007/s10762-010-9677-1

Cite this article as:
Karasawa, H., Komori, T., Watanabe, T. et al. J Infrared Milli Terahz Waves (2011) 32: 655. doi:10.1007/s10762-010-9677-1

Abstract

We experimentally observed the fast relaxation and relatively slow recombination dynamics of photogenerated electrons/holes in a heteroepitaxial graphene-on-Si material under pumping with a 1550-nm, 80-fs pulsed fiber laser and probing with the corresponding terahertz beam generated by and synchronized with the pumping laser. The time-resolved electric-nearfield intensity originating from the coherent terahertz photon emission is electrooptically sampled in total-reflection geometry. The Fourier spectrum fairly agrees the product of the negative dynamic conductivity and the expected THz photon spectrum reflecting the pumping photon spectrum. This phenomenon is interpreted as an amplified stimulated terahertz emission.

Keywords

GrapheneTerahertzNegative-dynamic conductivityPopulation inversionStimulated emissionGOSCoherent

Copyright information

© Springer Science+Business Media, LLC 2010