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

• 作者: Jingshu Guo Jiang Li Chaoyue Liu Yanlong Yin Wenhui Wang Zhenhua Ni Zhilei Fu Hui Yu Yang Xu Yaocheng Shi Yungui Ma Shiming Gao Limin Tong Daoxin Dai
• 来源期刊: 光：科学与应用（英文版）
• 年，卷（期）: 2020,（2）
• 所属期刊栏目: Original Articles
• 页码范围: 274-284
• 页数: 11页
• 语种: 英文

摘要

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 1.55μm 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 1.55μm and beyond. When operating at 2μm, the present photodetector has a responsivity of～70 mA/W and a setup-limited 3 dB bandwidth of>20 GHz. When operating at 1.55μm, 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.