High-performance silicon-graphene hybrid plasmonic waveguide photodetectors beyond 1.55??m.

ABSTRACT: Graphene has attracted much attention for the realization of high-speed photodetection for silicon photonics over a wide wavelength range. However, the reported fast graphene photodetectors mainly operate in the 1.55??m wavelength band. In this work, we propose and realize high-performance waveguide photodetectors based on bolometric/photoconductive effects by introducing an ultrathin wide silicon-graphene hybrid plasmonic waveguide, which enables efficient light absorption in graphene at 1.55??m and beyond. When operating at 2??m, the present photodetector has a responsivity of ~70?mA/W and a setup-limited 3?dB bandwidth of >20?GHz. When operating at 1.55??m, the present photodetector also works very well with a broad 3?dB bandwidth of >40?GHz (setup-limited) and a high responsivity of ~0.4?A/W even with a low bias voltage of -0.3?V. This work paves the way for achieving high-responsivity and high-speed silicon-graphene waveguide photodetection in the near/mid-infrared ranges, which has applications in optical communications, nonlinear photonics, and on-chip sensing.

SUBMITTER: Guo J 

PROVIDER: S-EPMC7048841 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature