Ultrahigh-speed graphene-based optical coherent receiver

Yilun Wang,Lei Tong,Xinliang Zhang,Xiang Li,Xiaoyan Gao,Yu Yu,Wentao Deng,Hailong Zhou,Xinyu Huang,Xi Xiao,Zhibin Jiang,Lei Ye

doi:10.1038/s41467-021-25374-0

Abstract

Graphene-based photodetectors have attracted significant attention for high-speed optical communication due to their large bandwidth, compact footprint, and compatibility with silicon-based photonics platform. Large-bandwidth silicon-based optical coherent receivers are crucial elements for large-capacity optical communication networks with advanced modulation formats. Here, we propose and experimentally demonstrate an integrated optical coherent receiver based on a 90-degree optical hybrid and graphene-on-plasmonic slot waveguide photodetectors, featuring a compact footprint and a large bandwidth far exceeding 67 GHz. Combined with the balanced detection, 90 Gbit/s binary phase-shift keying signal is received with a promoted signal-to-noise ratio. Moreover, receptions of 200 Gbit/s quadrature phase-shift keying and 240 Gbit/s 16 quadrature amplitude modulation signals on a single-polarization carrier are realized with a low additional power consumption below 14 fJ/bit. This graphene-based optical coherent receiver will promise potential applications in 400-Gigabit Ethernet and 800-Gigabit Ethernet technology, paving another route for future high-speed coherent optical communication networks.

Highlights

Graphene-based photodetectors have attracted significant attention for high-speed optical communication due to their large bandwidth, compact footprint, and compatibility with silicon-based photonics platform
The results demonstrate that our proposed graphenebased optical coherent receiver (OCR) exhibits ultrahigh-speed and high-quality reception for advanced modulation formats that encode information on both the amplitude and phase of the light
The OCR has been widely used in long-range optical communication systems owing to high receiving sensitivity

Summary

Introduction

Graphene-based photodetectors have attracted significant attention for high-speed optical communication due to their large bandwidth, compact footprint, and compatibility with silicon-based photonics platform. Receptions of 200 Gbit/s quadrature phase-shift keying and 240 Gbit/s 16 quadrature amplitude modulation signals on a single-polarization carrier are realized with a low additional power consumption below 14 fJ/bit This graphene-based optical coherent receiver will promise potential applications in 400-Gigabit Ethernet and 800-Gigabit Ethernet technology, paving another route for future high-speed coherent optical communication networks. The advanced modulation formats, including binary phase-shift keying (BPSK) up to 90 Gbit/s, quadrature phase-shift keying (QPSK) up to 200 Gbit/s (100 Gbaud), and 16 quadrature amplitude modulation (QAM) up to 240 Gbit/s (60 Gbaud), are successfully detected by the proposed graphene-based PDs with power consumption below 14 fJ/bit This proposed OCR implemented on a different-material mechanism takes the advantage of the combination of graphene optoelectronics, plasmonic sub-wavelength light confinement, and silicon photonics, all of which allow for efficient and highspeed detection on the μm-scale footprint

Methods

Results

Conclusion