Highly Efficient Dual Band Graphene Plasmonic Photodetector at Optical Communication Wavelengths

Graphene has remarkable properties in the optoelectronic field, especially in high speed photodetection. However, the responsivity of the graphene-based photodetectors is limited to tens of mA/W because of the weak absorption of the graphene layer. In this paper, a graphene plasmonic photodetector with high responsivity operating in two optical communication bands (O-band and U-band) is proposed. The combination of the graphene monolayer and the plasmonic structure is used to enhance the light-graphene interaction and consequently to improve the responsivity of the photodetector. The numerical simulation results show that the proposed photodetector has the responsivity of 348 mA/W and 460 mA/W at the wavelengths of 1310 nm and 1675 nm, respectively. Also, this structure exhibits the bandwidth of 60 GHz.