Ezra Ip NEC Labs AmericaEzra Ip is a Senior Researcher in the Optical Networking and Sensing Department at NEC Laboratories America. Ezra Ip received the B.E. degree (Hons.) in electrical and electronics engineering from the University of Canterbury, Christchurch, New Zealand, and the M.S. and Ph.D. degrees in electrical engineering from Stanford University. His doctoral thesis was on coherent detection and digital signal processing for optical communications.

He has published more than 100 journal articles and conference papers in the areas of high-capacity optical transmission, digital signal processing techniques, space-division multiplexing, and distributed fiber sensing. Dr. Ip has served on the topical program committees of OFC, ECOC, APC, and other conferences. He is an Associate Editor of IEEE Photonics Technology Letters. His research has shaped the development of digital signal processing techniques for optical systems, including modulation formats, phase recovery, and polarization multiplexing.

At NEC, he plays a key role in designing photonic subsystems for elastic optical networks and next-generation transport layers. His work continues to influence both academic and industrial research, particularly in scaling optical capacity and improving signal integrity over long-haul fiber links.

Posts

Leveraging Deployed Telecom Cables for Distributed Fiber Sensing Topologies and Applications

Distributed fiber optic sensing (DFOS) has emerged as a promising technology for wide-area monitoring by utilizing existing telecom cables as large-scale sensing media. This paper explores three sensing modalities, backscattering-based sensing, forward-transmission-based sensing, and hybrid sensing, and discusses their respective benefits, challenges, and application domains. Backscattering sensing demonstrates strong potential for applications such as road traffic monitoring, pavement condition assessment, intrusion detection, and cabledamage prevention but is constrained in amplified dense wavelength division multiplexing (DWDM) networks. Forward-transmission sensing enables sensing over operational telecom links with in-line amplification, extending sensing reach, although it involves trade-offs in spatial resolution and localization accuracy. To address these challenges, a hybrid sensing architecture that integrates backscattering and forward-transmission techniques is introduced, achieving enhanced sensing distance while maintaining high sensitivity and localization performance.In addition, this work incorporates artificial intelligence (AI) through a locally adaptive anomaly detection (LAAD) framework based on self-supervised representation learning. By leveraging location-based pretext tasks and unlabeled data, the proposed AI approach enables efficient adaptation across heterogeneous fiber routes and operational environments, significantly reducing reliance on labeled data while improving cross-domain generalization. Field trials over deployed telecom networks validate the feasibility and effectiveness of the proposedsensing and AI framework, demonstrating scalable, telecom-compatible DFOS for real-world infrastructure monitoring and intelligent network operations.

Frequency-Division Multiplexed Time-Interleaved Phase-OTDR with Nested Phase References

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.

NEC Labs America Attending OFC 2026 Los Angeles, March 15-19

NEC Laboratories America’s Optical Networking & Sensing team will participate in OFC 2026 in Los Angeles, March 15–19, contributing to panels, workshops, and courses focused on optical sensing, multicore fibers, and next-generation high-capacity optical communication systems.

Advances in Fiber Sensing

In this talk, we will present recent technological advances in fiber sensing applications with long monitoring distances orextending multiple fiber spans. In forward-transmission-based sensing, adaptive beamforming techniques weredemonstrated to achieve multi-event vibration sensing in environments with interference and jamming with significantimprovements in signal reconstruction, noise reduction, and interference rejection from other locations. For sensing oversubmarine cables with many fiber spans with repeaters, it is shown that distributed reflection from Rayleigh scattering canbe detected with sufficient SNR for fiber sensing using HLLB paths. In particular, longitudinal averaging of receivedRayleigh scattered signals can facilitate state-of-polarization-based, multi-span sensing using eigenvalue method.

Observing the Worst- and Best-Case Line-System Transmission Conditions in a C-Band Variable Spectral Load Scenario

We experimentally investigated variable spectral loading in an OMS, identifying performance under best and worst transmission conditions. Metrics and data visualization allowed correlation between channel configurations and OSNR variations, enabling the derivation of a simple spectrum allocation rule.

Toward Intelligent and Efficient Optical Networks: Performance Modeling, Co-existence, and Field Trials

Optical transmission networks require intelligent traffic adaptation and efficient spectrum usage. We present scalable machine learning (ML) methods for network performance modeling, andfield trials of distributed fiber sensing and classic optical network traffic coexistence.

Robust Phase Noise Power Spectral Density Estimation Using Multi-Laser Interferometry

We jointly estimate the phase noise power spectral densities of multiple lasers using interferometry between different combinations of laser pairs. We demonstrate a beat-frequency trackingmethod that allows under-sampling of interferometric products without phase jumps.

1.2 Tb/s/l Real Time Mode Division Multiplexing Free Space Optical Communication with Commercial 400G Open and Disaggregated Transponders

We experimentally demonstrate real time mode division multiplexing free space optical communication with commercial 400G open and disaggregated transponders. As proof of concept,using HG00, HG10, and HG01 modes, we transmit 1.2 Tb/s/l (3´1l´400Gb/s) error free.

Optical Line System Physical Digital Model Calibration using a Differential Algorithm

A differential algorithm is proposed to calibrate the physical digital model of an optical line system from scratch at the commissioning phase, using minimal measurements and maximizing signal and OSNR estimation accuracy.

Strain Accumulation Rate in Fiber Spools in the Presence of Ambient Acoustic Noise in Laser Phase Interferometry

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.