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arxiv: 2604.05205 · v1 · submitted 2026-04-06 · ⚛️ physics.optics

High-Resolution Coherent DFS Over 20km Ultra-Low-Loss Anti-Resonant Hollow-Core Fiber with Live Traffic

Rajiv Boddeda , Arnaud Dupas , Ha\"ik Mardoyan , Christian Dorize , Fabien Boitier , Peng Li , Zhang Lei , Jie Luo
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Pierre Brochard Carina Castineiras Jelena Pesic Florian Pulka J\'er\'emie Renaudier
This is my paper

Pith reviewed 2026-05-10 18:57 UTC · model grok-4.3

classification ⚛️ physics.optics
keywords coherent distributed fiber sensinghollow-core fiberanti-resonant fibersub-meter resolutiondistributed acoustic sensinglive traffic coexistenceultra-low loss fiber
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The pith

Stabilized laser enables sub-meter resolution coherent DFS over 20 km ultra-low-loss hollow-core fiber alongside live 1.2 Tbps traffic

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper demonstrates that coherent distributed fiber sensing can reach sub-meter spatial resolution when a stabilized laser is used on 20 km of anti-resonant hollow-core fiber with propagation loss below 0.10 dB/km. The same setup detects acoustic oscillations along the fiber. The sensing channel runs without measurable effect on 1.2 Tbps live traffic carried on an adjacent channel in the same fiber. A sympathetic reader would care because the result shows how high-resolution environmental monitoring can be added to operational high-capacity networks without installing separate fibers or interrupting service.

Core claim

The authors claim to have achieved sub-meter resolution coherent distributed fiber sensing on 20 km of anti-resonant hollow-core fiber with loss under 0.10 dB/km by using a stabilized laser source; the demonstration includes detection of acoustic oscillations while the sensing signal shares the fiber with 1.2 Tbps live traffic on the adjacent channel and produces no impact on that traffic.

What carries the argument

Stabilized-laser coherent DFS performed on anti-resonant hollow-core fiber, which supplies the low loss and phase stability needed for high-resolution sensing along the full link length.

If this is right

  • Distributed acoustic sensing becomes practical on long-haul spans without requiring separate sensing fibers.
  • Existing high-speed data links can add real-time environmental monitoring on the same physical fiber.
  • Sub-meter detection of vibrations supports applications such as intrusion detection or structural monitoring in deployed networks.
  • The ultra-low-loss hollow-core fiber preserves both sensing performance and data-channel integrity over extended distances.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same stabilized-laser approach might be tested on other hollow-core fiber designs or at higher data rates.
  • Integration with automated anomaly detection could turn the sensed data into actionable alerts for network operators.
  • Deployment in metropolitan or undersea cables could provide wide-area vibration monitoring alongside existing traffic.
  • Scaling the method to multi-parameter sensing by combining it with other scattering mechanisms remains an open extension.

Load-bearing premise

The 20 km anti-resonant hollow-core fiber and laser stabilization together deliver sub-meter resolution and zero interference with live traffic under the experimental conditions.

What would settle it

A test in which the observed spatial resolution exceeds one meter or the 1.2 Tbps traffic experiences bit errors when the DFS signal is active would disprove the central claim.

Figures

Figures reproduced from arXiv: 2604.05205 by Arnaud Dupas, Carina Castineiras, Christian Dorize, Fabien Boitier, Florian Pulka, Ha\"ik Mardoyan, Jelena Pesic, J\'er\'emie Renaudier, Jie Luo, Peng Li, Pierre Brochard, Rajiv Boddeda, Zhang Lei.

Figure 1
Figure 1. Figure 1: (a) The characteristics of the hollow core fiber are shown here (b) Standard OTDR trace of the HCF fiber acquired using few minutes of acquisition and with pulse duration ~ 100 ns. (c) The fit for the propagation losses using the difference between the forward and backward OTDR traces (d) Shows our HCF where we mount the spliced connection at 8.1kms on a translation stage to create acoustic excitations [P… view at source ↗
Figure 2
Figure 2. Figure 2: (a) High resolution coherent OTDR/DAS setup along with live traffic. (b) Spectrum of the transmitted signal showing the sensing channel (in black box) and the carrier next to it carrying live traffic. (b) Uncorrected code blocks at the traffic when the power at the input is varied showing no impact at high input powers [PITH_FULL_IMAGE:figures/full_fig_p002_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: (a) High resolution coherent DFS measurement as a function of distance. We show the FWHM of the two spliced peaks on the right (b) Normalized phase variation as a function of time where we induce artificially an oscillation in first 2 seconds and turn it off. (c) We show the PSD of the signal in the first and last 2 seconds [PITH_FULL_IMAGE:figures/full_fig_p003_3.png] view at source ↗
read the original abstract

We demonstrate sub-meter resolution Coherent DFS and detect acoustic oscillations using a stabilized laser on 20 km of anti-resonant HCF with <0.10 dB/km loss without impacting live traffic of 1.2 Tbps on the adjacent channel.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript reports an experimental demonstration of sub-meter resolution coherent distributed fiber sensing (Coherent DFS) over 20 km of anti-resonant hollow-core fiber (HCF) with loss below 0.10 dB/km. A stabilized laser is used to detect acoustic oscillations, with the sensing performed without impacting live 1.2 Tbps traffic on an adjacent WDM channel.

Significance. If the experimental claims hold, the work would be significant for integrating high-resolution distributed sensing with operational high-capacity telecom links in ultra-low-loss HCF, potentially enabling non-disruptive network monitoring applications without dedicated sensing fibers.

major comments (2)
  1. [Results] Results section: The central claim that the Coherent DFS probe produces 'no impact' on the adjacent 1.2 Tbps live traffic lacks quantitative validation such as before/after BER, Q-factor, or OSNR penalty measurements (or equivalent crosstalk spectra) under the stated launch powers and fiber conditions; wavelength separation and low HCF loss alone do not guarantee this outcome in a live WDM system.
  2. [Abstract and Experimental Setup] Experimental setup and abstract: The sub-meter spatial resolution and acoustic oscillation detection are asserted without reported data, error bars, or verification details (e.g., against a calibrated acoustic source or known fiber perturbation), preventing assessment of whether the results support the stated performance.
minor comments (1)
  1. [Abstract] The abstract is concise but omits any mention of the specific stabilization technique or wavelength allocation details for the sensing and traffic channels.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the detailed and constructive review. The comments highlight important aspects of quantitative validation and clarity in presenting our experimental results. We address each major comment below and have revised the manuscript to strengthen the presentation of our claims.

read point-by-point responses

  1. Referee: [Results] Results section: The central claim that the Coherent DFS probe produces 'no impact' on the adjacent 1.2 Tbps live traffic lacks quantitative validation such as before/after BER, Q-factor, or OSNR penalty measurements (or equivalent crosstalk spectra) under the stated launch powers and fiber conditions; wavelength separation and low HCF loss alone do not guarantee this outcome in a live WDM system.

    Authors: We agree that quantitative validation is required to rigorously support the 'no impact' claim in a live WDM system. While the original manuscript emphasized the large wavelength separation (adjacent channel) and the ultra-low loss (<0.10 dB/km) of the anti-resonant HCF to argue for negligible crosstalk, we acknowledge these factors alone are insufficient without direct measurements. In the revised manuscript, we have added before-and-after BER and Q-factor data for the 1.2 Tbps traffic channel, measured under the exact launch powers and fiber conditions used in the experiment. These results confirm no measurable penalty, and we have included the corresponding spectra and uncertainty estimates in the updated Results section. revision: yes

  2. Referee: [Abstract and Experimental Setup] Experimental setup and abstract: The sub-meter spatial resolution and acoustic oscillation detection are asserted without reported data, error bars, or verification details (e.g., against a calibrated acoustic source or known fiber perturbation), preventing assessment of whether the results support the stated performance.

    Authors: The manuscript presents supporting experimental data for both the sub-meter resolution and acoustic detection in the Results section (Figures 2–4), including spatial response profiles and time-frequency plots of detected oscillations. To directly address the concern, we have expanded the Experimental Setup section with additional verification details: the use of a calibrated acoustic source at a known location and frequency, the procedure for confirming the perturbation, and error bars derived from repeated measurements. We have also updated the abstract to briefly reference these quantitative elements for improved clarity. revision: yes

Circularity Check

0 steps flagged

No circularity: experimental demonstration with no derivations or fitted predictions

full rationale

The paper reports an experimental demonstration of sub-meter resolution coherent DFS over 20 km of anti-resonant hollow-core fiber while coexisting with live 1.2 Tbps traffic. No equations, theoretical derivations, parameter fits, or predictions appear in the provided abstract or claimed results. The central assertions rest on direct measurements of resolution, acoustic detection, fiber loss, and traffic compatibility rather than any self-referential construction, self-citation chain, or renaming of inputs as outputs. The absence of a derivation chain means no load-bearing step reduces to its own inputs by construction.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

As an experimental demonstration, the claim rests on standard optical physics and measurement techniques rather than new theoretical constructs; no free parameters, ad-hoc axioms, or invented entities are introduced.

axioms (1)
  • standard math Standard principles of light propagation, interference, and fiber optics apply to coherent DFS measurements.
    The demonstration relies on established optical physics without introducing new axioms.

pith-pipeline@v0.9.0 · 5387 in / 1297 out tokens · 157445 ms · 2026-05-10T18:57:45.532276+00:00 · methodology

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Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

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Reference graph

Works this paper leans on

8 extracted references · 8 canonical work pages

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    Hollow Core DNANF Optical Fiber with <0.11 dB/km Loss,

    Y. Chen, et al., "Hollow Core DNANF Optical Fiber with <0.11 dB/km Loss," in OFC 2024, paper Th4A.8

    work page 2024

  2. [2]

    Theoretical analysis of backscattering in hollow-core antiresonant fibers

    E. Numkam Fokoua, et al., "Theoretical analysis of backscattering in hollow-core antiresonant fibers" APL Photonics 2021; 6 (9): 096106

    work page 2021

  3. [3]

    First Field Demonstration of Hollow-Core Fibre Supporting Distributed Acoustic Sensing and DWDM Transmission,

    E. Ip et al., "First Field Demonstration of Hollow-Core Fibre Supporting Distributed Acoustic Sensing and DWDM Transmission," in ECOC, paper Th1F.1, 2024

    work page 2024

  4. [4]

    Distributed Characterization of Low-loss Hollow Core Fibers using EDFA-assisted Low-cost OTDR instrument,

    X. Wei et al., "Distributed Characterization of Low-loss Hollow Core Fibers using EDFA-assisted Low-cost OTDR instrument," OFC 2023

    work page 2023

  5. [5]

    Optical time domain backscattering of antiresonant hollow core fibers,

    R. Slavík et al., "Optical time domain backscattering of antiresonant hollow core fibers," Opt. Express 30, 31310-31321 (2022)

    work page 2022

  6. [6]

    Backscattering in antiresonant HCF: f ,

    V. Michaud-Belleau, et al., "Backscattering in antiresonant HCF: f ," O , -219 (2021) [7 , " …," EEE JL , , , -1063, 15 Feb.15, 2023

    work page 2021

  7. [7]

    Demonstration of MIMO-DFS over 100km of unamplified SSMF Link using Active Laser Drift Stabilization and Optimized Probing Codes

    R. Boddeda et , “Demonstration of MIMO-DFS over 100km of unamplified SSMF Link using Active Laser Drift Stabilization and Optimized Probing Codes” O ,

    work page

  8. [8]

    Low loss and broadband low back -reflection interconnection between a hollow-core and standard single-mode fiber,

    D. Suslov et al., " Low loss and broadband low back -reflection interconnection between a hollow-core and standard single-mode fiber," Opt. Express 30, 37006-37014 (2022). Figure 3: (a) High resolution coherent DFS measurement as a function of distance. We show the FWHM of the two spliced peaks on the right (b) Normalized phase variation as a function of ...

    work page 2022