Yu Laiwen, Li Yurui, Xiang Hengtai, Li Yuanrong, Cao Hengzhen, Ji Zhongyang, Liu Liu, Xiao Xi, Yin Jianbo, Guo Jingshu, Dai Daoxin
State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Zijingang Campus, Hangzhou 310058, China.
State Key Laboratory of Advanced Optical Communications System and Networks, School of Electronics, Peking University, Beijing 100871, P.R. China.
Nanophotonics. 2024 Jul 31;13(21):4019-4028. doi: 10.1515/nanoph-2024-0274. eCollection 2024 Sep.
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.
具有低功耗和低制造成本优势的硅光子学是促进高容量光通信和互连的关键技术。具有宽带运行、高速和低集成成本特点的石墨烯光电探测器（GPD）可以很好地补充硅锗光电探测器，支持在硅上1.6μm以上波段的高速光电探测。在此，我们基于微环谐振器（MRR）阵列和四个p-n同质结GPD实现了一种硅集成四通道波分复用（WDM）光接收器。这些光热（PTE）GPD表现出约1.1V/W的零偏置响应度，且设置限制3dB带宽>67GHz。得益于由单个机械剥离的hBN/石墨烯/hBN堆栈覆盖的紧凑有源区阵列（0.006mm），这些GPD显示出良好的一致性。此外，该WDM石墨烯光接收器实现了4×16Gbps的非归零光信号传输。据我们所知，这是首个基于GPD阵列的光接收器，它使用了高质量的机械剥离石墨烯和具有低电阻的边缘石墨烯-金属接触。显然，我们的设计也与化学气相沉积（CVD）生长的石墨烯兼容。这项工作为具有高一致性和均匀性的GPD大规模集成提供了思路，使得高质量的机械剥离石墨烯得以应用，并推动了石墨烯光子集成电路的发展。
