光通信研究Issue(4)：18-28,11.DOI:10.13756/j.gtxyj.2026.260128
面向AI超节点互连的简化相干光通信技术(特邀)
Simplified Coherent Technology for AI Supernode Optical Interconnects
摘要
Abstract
[Objective]Due to the multi-dimensional modulation capability,coherent technology is emerging as a core evolution-ary direction for high-speed intelligent computing optical interconnects.However,the high cost and power consumption remain key bottlenecks restricting its deployment in short-reach scenarios.To effectively reduce its implementation cost and power con-sumption while maintaining the advantages of high-capacity and high-performance,simplified coherent technologies for Artificial Intelligence(AI)supernode interconnects have become a hot research topic.[Methods]To tackle the cost and power bottle-necks inherent in conventional coherent architectures,this article systematically reviews existing simplified coherent solutions from three perspectives:low-cost phase/frequency-locking techniques,hardware-efficient Digital Signal Processing(DSP)algo-rithms,and real-time implementations.In terms of low-cost phase/frequency-locking techniques,a frequency offset locking scheme based on pre-scanning combined with Fast Fourier Transform(FFT)and Chirp Z-Transform(CZT),as well as a digital heterodyne optical phase-locked loop scheme combining coarse frequency offset acquisition with fine phase tracking,are proposed to avoid using expensive narrow-linewidth lasers.As for hardware-efficient DSP algorithms,a single-pilot-tone-based polariza-tion demultiplexing method and a novel baud-rate 3Sign-Timing Error Detector(TED)scheme based on sign operations are pro-posed to reduce the hardware requirements of the equalization and clock recovery modules.Besides,a low-complexity real-time coherent system is verified based on 32 Gbaud dual-polarization Quadrature Phase Shift Keying(QPSK)signals.[Results]Ex-perimental results demonstrate that the proposed phase/frequency-locking techniques can effectively ensure frequency-locking ac-curacy and frequency stability,with frequency fluctuation suppressed within 200 kHz.In terms of simplified equalization,the pro-posed scheme not only reduces the complexity of the equalization module but also improves the polarization tracking speed to 10 Mrad/s.As for the clock recovery,the proposed 3Sign-TED scheme can effectively avoid any multiplication operations,ex-hibiting extremely low hardware complexity.Furthermore,based on the 32 Gbaud dual-polarization QPSK real-time coherent platform,a low-complexity real-time coherent system with a net data rate exceeding 100 Gbit/s is successfully demonstrated.[Conclusion]The above technical breakthroughs provide a reference for future high-speed optical interconnects in AI data cen-ters.关键词
智算中心光互连/简化相干光通信技术/锁相/锁频技术/实时相干系统/空芯光纤传输Key words
AI data center interconnects/simplified coherent technology/phase/frequency-locking techniques/real-time coherent system/hollow-core fiber transmission分类
信息技术与安全科学引用本文复制引用
王玮,李祖宇,董铠阳,李凡..面向AI超节点互连的简化相干光通信技术(特邀)[J].光通信研究,2026,(4):18-28,11.基金项目
国家科技部重点研发计划青年科学家资助项目(2023YFB2906000) （2023YFB2906000）
国家自然科学联合基金重点资助项目(U25B2011) （U25B2011）
国家自然科学基金资助项目(62271517,U2001601,62035018) （62271517,U2001601,62035018）
广东省基础与应用基础研究资助项目(2023B1515020003) （2023B1515020003）
