• 文献标题:   Mechanism of propagating graphene plasmons excitation for tunable infrared photonic devices
  • 文献类型:   Article
  • 作  者:   TANG LL, WEI W, WEI XZ, NONG JP, DU CL, SHI HF
  • 作者关键词:  
  • 出版物名称:   OPTICS EXPRESS
  • ISSN:   1094-4087
  • 通讯作者地址:   Chinese Acad Sci
  • 被引频次:   7
  • DOI:   10.1364/OE.26.003709
  • 出版年:   2018

▎ 摘  要

The mechanism of propagating graphene plasmons excitation using a nano-grating and a Fabry-Perot cavity as the optical coupling components is studied. It is demonstrated that the system could be well described within the temporal coupled mode theory using two phenomenological parameters, namely, the intrinsic loss rate and the coupling rate of a graphene plasmonic mode, and their analytical expressions are derived. It is found that the intrinsic loss rate is solely determined by the electron relaxation time of graphene, while independent of the field distributions of the modes. Such result originates from the negligible magnetic field energy of the graphene plasmonic mode. The coupling rate is governed by the optical coupling components parameters, and varies periodically with the Fabry-Perot cavity length. By modulating the two rates, quality factors and absorption rates can be adjusted. Furthermore, it is revealed that low refractive index of the Fabry-Perot cavity material is vital to the enlargement of tunable band, and the underlying physics is discussed. Such plasmon excitation configuration is insensitive to light incident angle and could serve as a platform for many tunable infrared photonic device, such as surface-enhanced infrared absorption spectroscopies, infrared detectors and modulators. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement