OPTICAL NETWORKING & SENSING
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Optical Networking & Sensing
Junqiang Hu is a Senior Researcher in the Optical Networking and Sensing Department at NEC Laboratories America. He received his PhD in EE and Communication from the University of Science and Technology of China.
At NEC Labs America, Dr. Hu’s work bridges advanced fiber-optic communications with distributed sensing applications. His recent projects include investigating how ambient acoustic noise affects the accumulation of phase noise in fiber spools. He also contributed to a pioneering field demonstration of hollow-core fiber, enabling both distributed acoustic sensing (DAS) and dense wavelength-division multiplexing (DWDM) transmission. Hu plays a key role in NEC’s SensSA project, which aims to boost the performance and integration of distributed fiber-optic sensors (DFOS) in real-world systems.
He is a co-inventor on several recent patents, including techniques to suppress dynamic-range noise in two-stage DAS interrogation systems (granted in July 2024) and innovations in coded temperature sensing for enhanced data security (granted in March 2025). His contributions focus on improving measurement precision, spatial resolution, and the coexistence of sensing and data transmission, advancing DFOS as a dual-use technology for telecom and infrastructure monitoring.
We propose a method to compensate the phase offset between samples from different tributaries in time-interleaved phase OTDR using nested phase reference channels. We demonstrate our method for a four-span bidirectional link with high-loss loopback.
We investigate the growth rate of phase power spectral density in fiber spools in the presence of ambient acoustic noise, observing a complex interplay between spool geometry, shielding effects, and phase cancellation at high acoustic frequencies.
We demonstrate a method for measuring the backscatter coefficient of hollow-core fibre (HCF), and show the feasibility of distributed acoustic sensing (DAS) with simultaneous 9.6-Tb/s DWDM transmission over a 1.6-km field-deployed HCF cable.
Optical fiber cables, initially designed for telecommunications, are increasingly repurposed for environmental monitoring using distributed fiber sensing technologies [1,2]. Distributed acoustic sensing (DAS) based on phase optical time domain reflectometry (?-OTDR) of Rayleigh backscatter enables various
We report significant noise reduction in distributed acoustic sensing (DAS) link using enhanced-scatter fibre (ESF). The longest reach of 195km DAS link without inline amplifications is also demonstrated. We further present demonstration of simultaneous fibre-optic sensing and 400Gb/s data transmissions
We demonstrate, for the first time, real-time blind source separation of interfering GHz transmitters using photonic weights controlled by an RF-System-on-Chip FPGA. This analog system achieves multi-antenna signal separation with millisecond execution latency.
We explore two fiber sensing methods which enables coexistence with data transmission on DWDM fiber networks. Vibration detection and localization can be achieved by extracting optical phase from modified coherent transponders. Frequency-diverse chirped-pulse DAS with all-Raman amplification can improve
