76 citations · 245 across the 13 of their papers we have counts for
13 papers
OSNR/GSNR Prediction in Brownfield Links via a DLM-Anchored Hybrid Physics/ML Model
Agastya Raj, Venkata Virajit Garbhapu, Hiroyuki Ishihara +5
We present a DLM-anchored hybrid physics/ML framework for brownfield optical links that accurately predicts per-channel power, OSNR, and GSNR. Calibrating span/ILA boundaries via D…
Leveraging Digital Twin Technologies: All-Photonics Networks-as-a-Service for Data Center Xchange in the Era of AI [Invited Tutorial]
Hideki Nishizawa, Kazuya Anazawa, Tetsuro Inui +8
This paper presents a data center exchange (Data Center Xchange, DCX) architecture for all-photonics networks-as-a-service in distributed data center infrastructures, enabling the…
Optical Network Digital Twin -- Practical Use Cases and Architecture
Hideki Nishizawa, Toru Mano, Kazuya Anazawa +17
With the widespread adoption of AI, machine-to-machine communications are rapidly increasing, reshaping the requirements for optical networks. Recent advances in Gaussian noise mod…
Optical Link Tomography: First Field Trial and 4D Extension
Takeo Sasai, Giacomo Borraccini, Yue-Kai Huang +11
Optical link tomography (OLT) is a rapidly evolving field that allows the multi-span, end-to-end visualization of optical power along fiber links in multiple dimensions from networ…
Beyond Redundancy: Toward Agile Resilience in Optical Networks to Overcome Unpredictable Disasters
Toru Mano, Hideki Nishizawa, Takeo Sasai +9
Resilience in optical networks has traditionally relied on redundancy and pre-planned recovery strategies, both of which assume a certain level of disaster predictability. However,…
Design of Fiber-Longitudinal Optical Power Monitor
Takeo Sasai, Sze Yun Set, Shinji Yamashita
This paper presents analytical results on the accuracy of fiber-longitudinal optical power monitoring (LPM) at arbitrary positions. To quantify the accuracy, the position-wise vari…
Semi-Automatic Line-System Provisioning with Integrated Physical-Parameter-Aware Methodology: Field Verification and Operational Feasibility
Hideki Nishizawa, Giacomo Borraccini, Takeo Sasai +17
We propose methods and an architecture to conduct measurements and optimize newly installed optical fiber line systems semi-automatically using integrated physics-aware technologie…
Linear Least Squares Estimation of Fiber-Longitudinal Optical Power Profile
Takeo Sasai, Minami Takahashi, Masanori Nakamura +2
This paper presents a linear least squares method for fiber-longitudinal power profile estimation (PPE), which estimates an optical signal power distribution throughout a fiber-opt…
Performance Limit of Fiber-Longitudinal Power Profile Estimation Methods
Takeo Sasai, Etsushi Yamazaki, Yoshiaki Kisaka
This paper presents analytical results on longitudinal power profile estimation (PPE) methods, which visualize signal power evolution in optical fibers at a coherent receiver. The…
Dynamic optical path provisioning for alien access links: architecture, demonstration, and challenges
Hideki Nishizawa, Takeo Sasai, Takeru Inoue +6
With the spread of Data Center Interconnect (DCI) and local 5G, there is a growing need for dynamically established connections between customer locations through high-capacity opt…
Physics-oriented learning of nonlinear Schrödinger equation: optical fiber loss and dispersion profile identification
Takeo Sasai, Masanori Nakamura, Etsushi Yamazaki +3
In optical fiber communication, system identification (SI) for the nonlinear Schrödinger equation (NLSE) has long been studied mainly for fiber nonlinearity compensation (NLC). One…
Laser Phase Noise Tolerance of Uniform and Probabilistically-shaped QAM Signals for High Spectral Efficiency Systems
Takeo Sasai, Asuka Matsushita, Masanori Nakamura +3
We numerically and experimentally investigate the laser phase noise tolerance of probabilistically shaped (PS) and uniformly shaped (US) quadrature amplitude modulation (QAM) signa…
Wiener-Hammerstein model and its learning for nonlinear digital pre-distortion of optical transmitters
Takeo Sasai, Masanori Nakamura, Etsushi Yamazaki +4
We present a simple nonlinear digital pre-distortion (DPD) of optical transmitter components, which consists of concatenated blocks of a finite impulse response (FIR) filter, a mem…