Four-channel graphene optical receiver

• Published in: Nanophotonics (Berlin, Germany) Germany), 2024-09, Vol.13 (21), p.4019-4028
• Main Authors: Yu, Laiwen, Li, Yurui, Xiang, Hengtai, Li, Yuanrong, Cao, Hengzhen, Ji, Zhongyang, Liu, Liu, Xiao, Xi, Yin, Jianbo, Guo, Jingshu, Dai, Daoxin
• Format: Article
• Language: English
• Subjects: Arrays; Broadband; Graphene; graphene photodetectors; Homojunctions; Integrated circuits; optical receiver; Optical receivers; photo-thermoelectric effect; Photometers; Photonics; Production costs; Signal transmission; silicon photonics; Wave division multiplexing; Wavelength division multiplexing
• ISSN: 2192-8614; 2192-8606; 2192-8614
• DOI: 10.1515/nanoph-2024-0274

Silicon photonics with the advantages of low power consumption and low fabrication cost is a crucial technology for facilitating high-capacity optical communications and interconnects. The graphene photodetectors (GPDs) featuring broadband operation, high speed, and low integration cost can be good additions to the SiGe photodetectors, supporting high-speed photodetection in wavelength bands beyond 1.6 μm on silicon. Here we realize a silicon-integrated four-channel wavelength division multiplexing (WDM) optical receiver based on a micro-ring resonator (MRR) array and four p-n homojunction GPDs. These photo-thermoelectric (PTE) GPDs exhibit zero-bias responsivities of ∼1.1 V W and set-up limited 3 dB-bandwidth >67 GHz. The GPDs show good consistence benefiting from the compact active region array (0.006 mm ) covered by a single mechanically exfoliated hBN/graphene/hBN stack. Moreover, the WDM graphene optical receiver realized 4 × 16 Gbps non-return-to-zero optical signal transmission. To the best of our knowledge, it is the first GPD-array-based optical receiver using high-quality mechanically exfoliated graphene and edge graphene-metal contacts with low resistances. Apparently, our design is also compatible with CVD-grown graphene. This work sheds light on the large-scale integration of GPDs with high consistency and uniformity, enabling the application of high-quality mechanically exfoliated graphene, and promoting the development of the graphene photonic integrated circuits.