Pith. sign in

REVIEW 5 major objections 5 minor 53 references

Entanglement-based quantum key distribution with data in hollow-core fiber

T0 review · 5 major / 5 minor · reviewed 2026-08-01 · deepseek-v4-flash

Challenge this review Re-run · record.json Download PDF Read on arXiv ↗

Pith's one-line read Entanglement-based quantum keys can share an 18-km hollow-core fiber with 0 dBm bidirectional classical data, sustaining 10.56 kbps over 24 hours.

desk verdict A credible record-claim experiment, but the SKR inconsistency and the missing simulation appendix undercut the 200-km extrapolation. read the letter →

arxiv 2607.25331 v1 pith:6C6XJCRA submitted 2026-07-28 quant-ph

Yue Luo , Sheng Liu , Yun-Ru Fan , Da-Wei Ge , Zhi-Yang Liu , Hao Li , Si Shen , Zi-Chang Zhang
show 6 more authors
Hai-Zhi Song Li-Xing You Tao Zhou Kai Guo Guang-Can Guo Qiang Zhou
This is my paper
classification quant-ph PACS 03.67.Dd42.81.-i
keywords hollow-corefiberentanglement-basedQKDquantum-classicalcoexistencehigh-dimensionalencodingtime-binentanglementRamanscatteringsuppressionopticalnetworkintegration
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper's central claim is that entanglement-based, time-encoded high-dimensional quantum key distribution can share an optical fiber with strong classical data traffic, provided the fiber is hollow-core. In an 18-km hollow-core fiber carrying bidirectional classical channels at 0 dBm received power (about 1 milliwatt), the system generated an average secret key rate of 10.56 kbps over 24 hours, with time- and phase-basis error rates of 16.00% and 15.86%, both below the 21.7% threshold for 8-dimensional encoding. The reason this is possible is that hollow-core fibers suppress spontaneous Raman scattering by two to three orders of magnitude compared with standard silica fibers, removing the dominant nonlinear noise that otherwise contaminates weak quantum signals. If the result holds, quantum key distribution and conventional data channels can be integrated into the same fiber infrastructure without a separate dark fiber, and projections suggest rates above 135 kbps over more than 200 km with lower-loss hollow-core fibers.

What carries the argument

The enabling mechanism is the hollow-core fiber (HCF), which guides light in air rather than silica, cutting the Raman and four-wave mixing noise that plagues standard fibers. On top of this physical layer sits a continuous-window three-level time-sifting scheme for energy-time entangled photon pairs: arrival times are divided into frames and slots (d=8), and a sliding 85-ps window pairs correlated detections more efficiently than discrete time bins, conceptually analogous to mode pairing. The phase basis uses Franson interference to estimate the phase error rate. Together these allow high-dimensional key generation while classical data co-propagates.

What would settle it

Measure the secret key rate and QBER on a 100+ km low-loss hollow-core fiber link with 0 dBm received classical power and compare to the paper's projected curve; a large shortfall or QBER above the 21.7% d=8 threshold would falsify the scaling model. A more targeted test is to evacuate or gas-fill the hollow core and watch whether the excess noise observed in the loss-equivalent comparison disappears, identifying the residual-gas contribution.

Watch

Extended reading notes

Core claim

The paper reports an experimental demonstration in which time-encoded high-dimensional QKD (d=8, three bits per frame) runs simultaneously with bidirectional classical data on an 18-km hollow-core fiber. Classical channels are wavelength-multiplexed in the C and L bands with 0 dBm received power, and the quantum channels operate at C-band wavelengths. Using an 80:20 splitter to route photons to time- and phase-basis measurements, a continuous-window time-sifting scheme recovers temporal correlations, and the measured Franson visibility of 89–92% translates to QBERs near 16%, below the 21.7% threshold. The authors also measure forward Raman scattering coefficients and find them suppressed by

Load-bearing premise

The long-distance projection depends on the Raman-noise scaling measured on the 18-km fiber continuing to hold for lower-loss hollow-core fibers, and on none of the unquantified residual-gas noise sources identified in the paper growing with distance or classical power.

Editorial extensions

If this is right

  • A single hollow-core fiber can carry both entanglement-based key material and classical data channels at 0 dBm received power (up to about 2.3 Tbps theoretical classical capacity) without the quantum channel collapsing.
  • The measured forward Raman coefficient of hollow-core fiber is two to three orders of magnitude below that of standard single-mode fiber, establishing the physical basis for coexistence.
  • With lower-loss hollow-core fibers, the same setup is projected to sustain an SKR above 135 kbps past 200 km, putting it in range of practical backbone links.
  • The d=8 encoding yields about 0.62 secret bits per coincident detection under full coexistence, showing high-dimensional encoding pays off even in noisy conditions.
  • Continuous 24-hour operation with stable visibility and positive SKR indicates the approach is compatible with always-on network service.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the residual-gas Raman noise the paper identifies but does not quantify is a plausible candidate for the gap between the 18-km HCF and loss-equivalent B2B under classical load; a gas-evacuation or gas-exchange experiment would test this directly.
  • Editorial inference: the distance projection would be tested most directly by repeating the coexistence run on a low-loss hollow-core fiber at 100–200 km; an SKR shortfall or QBER above the d=8 threshold would indicate a new noise floor.
  • Editorial inference: the continuous-window time-sifting scheme may transfer to other energy-time high-dimensional protocols, such as dispersion-based QKD, where frame-based pairing could improve resilience to classical crosstalk.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

5 major / 5 minor

Summary. The manuscript reports an entanglement-based high-dimensional time-encoded QKD experiment coexisting with bidirectional classical data channels over an 18-km hollow-core fiber link. The classical channels operate at 0 dBm received power; the QKD uses energy-time entangled photon pairs with d=8 time-bin encoding and a continuous-window time-sifting scheme. The main measured results are an average secret key rate of 10.56 kbps over 24 h, with time- and phase-basis QBERs of 16.00% and 15.86%, below the stated 21.70% threshold for 8-dimensional encoding. A back-to-back loss-equivalent comparison and a power scan are used to characterize the influence of the fiber and the classical channels. The authors further present a theoretical extrapolation, based on a model in Supplementary Sections V–VII, predicting SKRs above 135 kbps over more than 200 km with lower-loss hollow-core fibers.

Significance. If the experimental numbers and the theoretical projection are correct, this would be the highest reported coexistence SKR at 0 dBm classical power in a hollow-core fiber and an important step toward practical quantum-classical networks. The direct measurement of Raman coefficients and the inclusion of a loss-equivalent B2B reference are useful methodological strengths. However, the central scalability claim rests on a supplementary model that is not included in the preprint, and the model is not validated against the 18-km coexistence data. The internal inconsistency between the stated maximum and the 24-h average SKR, together with missing error bars on the headline quantities, additionally weakens the quantitative claim.

major comments (5)
  1. [Fig. 3(e) vs. Fig. 4(d)] The paper states in Section III that the maximum SKR is 10.43 kbps at a pump power of 22 mW, while Section III and the abstract report an average SKR of 10.56 kbps over 24 h at the same optimal pump power. An average cannot exceed the maximum of the same quantity under the same operating point. Please clarify whether the 10.43 kbps value is from a short-term power scan with different optimization conditions, and provide the full distribution or uncertainty of the 24-h time series. As written, this inconsistency undermines the reliability of the headline rate.
  2. [Supplementary Sections V–VII and Fig. 5] The >135 kbps over >200 km projection is a headline claim, but the simulation framework, parameter values, and optimization details are confined to Supplementary Sections V–VII, which are not present in the preprint. Without the equations for the noise model, the entanglement-source parameters, and the joint optimization over d, pump power, and T_w, the dashed/solid curves in Fig. 5 cannot be independently reproduced or assessed. The authors should supply the complete supplement or move the essential derivations into the main text before a reliable evaluation is possible.
  3. [Table I and Appendix A.1] Table I shows that under classical signals the 18-km HCF achieves SKR 10.43 kbps with QBERs near 16%, whereas the loss-equivalent B2B+VOA reference achieves 19.82 kbps with QBERs near 9.8%. The text attributes this gap to residual-gas Raman noise, but Appendix A.1 states that a quantitative evaluation of gas versus silica contributions is 'beyond the scope of this work.' The simulation uses measured Raman coefficients, so it should be able to reproduce this measured 18-km gap; no such validation is shown. If the unexplained excess noise scales differently with length or classical power than assumed in the model equations, the >200 km projection is not supported. This validation is load-bearing for the central scalability claim.
  4. [Eq. (2) and error reporting] The text says that e_p is estimated from the Franson visibility V using Eq. (2), but Eq. (2) is written for e_b. The numerical values in Table I labeled e_p match the formula with d=8, suggesting a labeling typo, but it obscures the phase-error estimation. In addition, the QBER and SKR values in Table I and the 24-h averages in Fig. 4 are reported without error bars. Since the time- and phase-basis QBERs (16.00% vs. 15.86%) and the SKR fluctuations are central quantities, the reader cannot assess their statistical significance or stability. Please report standard errors or confidence intervals.
  5. [Eq. (1) and finite-key regime] The SKR formula in Eq. (1) is an asymptotic expression. The paper uses it to quote a 24-h average 'secret key rate' without a finite-key analysis. Over a 24-h run with finite block sizes, the finite-key correction may be significant; the authors themselves list finite-key analysis as future work. At minimum, the abstract and conclusions should clearly state that the quoted rate is asymptotic, and the impact of finite-key effects on the 24-h number should be discussed or bounded.
minor comments (5)
  1. [Section II] The attenuation is given as '0.27 km^{-1}'; this should be stated as 0.27 dB/km (or the conversion made explicit) to avoid confusion between linear and logarithmic units.
  2. [Section III] The sentence introducing the protocol says 'we implement a continuous-window-based three-level time-sifting HD-QKD protocol' but then refers to it as 'time-encoded high-dimensional QKD.' Please unify terminology and define the three levels explicitly.
  3. [Section III / Fig. 3(d)] The visibility curve in Fig. 3(d) is described as 'gradually decreasing with increasing pump power,' but the plotted values stay within a few percent. A quantitative fit or a statement of the slope would be more informative.
  4. [Section IV] The claim that the classical capacity is 'up to 2.3 Tbps' relies on Shannon's formula but no bandwidth, OSNR, or modulation assumptions are given. Please provide the calculation basis.
  5. [References] Several references are dated 2026 (e.g., [16], [17], [2], [9]). If these are not yet published in final form, please verify that they are available and correctly cited.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: key quantities are measured directly, the security formulas are external standard results, and the distance projection is an extrapolation model rather than a fitted restatement of the target.

full rationale

The central experimental claim (10.56 kbps average SKR over an 18-km HCF with 0 dBm bidirectional classical coexistence) is supported by direct measurements: sifted rates, visibility, QBERs, and coincidence statistics. The SKR is computed with Eq. (1), attributed to refs. [32,33], and the phase-basis QBER is related to Franson visibility through Eq. (2), attributed to ref. [32]; these are external protocol formulas, not parameters fitted to the present data. The Raman suppression claim is backed by directly measured forward Raman coefficients in Fig. 1(d,e), not by a self-citation. The >200 km / >135 kbps projection depends on Supplementary Sections V–VII, which are not included, and Appendix A.1 explicitly states that quantitative attribution of residual-gas versus silica Raman noise is 'beyond the scope of this work'; this is a real validation gap and a correctness risk, but it is not circularity because the simulation is not shown to be constructed so as to force the target SKR. Self-citations such as refs. [15,35,37] appear as prior demonstrations or comparisons and are not load-bearing for the main derivation. The apparent inconsistency between the 10.43 kbps maximum in Fig. 3(e) and the 10.56 kbps 24-hour average in Fig. 4(d) is a data-consistency concern, not a circularity. Overall, no step in the paper's derivation reduces to its own inputs by construction.

Assumptions & free parameters 5 free parameters · 4 assumptions · 0 invented entities

The central claim depends mainly on the protocol security proof imported from refs [32,33], the visibility-to-error mapping Eq. (2), the measured Raman coefficients, and the supplementary simulation model. The free parameters are system operating points (pump power, window width, classical wavelength, f(e), d), many of which are optimized to maximize SKR in the distance simulation.

free parameters (5)
  • continuous-window width T_w = 85 ps (experiment); jointly optimized in simulation
    The time-window width is selected to suppress noise; in Table I, the lower SKR of B2B+VOA coexistence is attributed to a smaller T_w chosen for the HCF case. In the simulations, T_w is jointly optimized at each distance to maximize SKR (Sec. V).
  • pump power = 22 mW (experiment); jointly optimized in simulation
    Pump power is scanned to maximize SKR (Fig. 3e); used as an optimization parameter in the distance extrapolation.
  • classical channel wavelength lambda_c = 1564.68 nm
    Selected as the wavelength with lowest accidental coincidences / highest CAR in Fig. 2(c-d); a data-driven choice.
  • error correction efficiency f(e) = 1.2
    Set to 1.2 in Eq. (1); standard assumption but a free parameter in the key-rate calculation.
  • time-encoded dimension d = 8
    Chosen encoding dimension; in simulations d is jointly optimized at each distance.
assumptions (4)
  • domain assumption The security proof of the d-level time-bin QKD protocol (from refs [32,33]) applies to the implemented continuous-window three-level time-sifting scheme.
    The key-rate formula Eq. (1) is imported from prior work; the paper only says the continuous-window scheme is 'conceptually similar to the mode-pairing strategy' but no security proof is re-derived for this exact sifting. This is load-bearing for the claim that the 10.56 kbps is secure key.
  • domain assumption The Franson-interference visibility V maps to phase-basis QBER via Eq. (2).
    Eq. (2) (e_p = 1/2 - V/(d - V(d-2))) is taken from ref [32]; it must hold for the 8-dimensional time-bin encoding under the experimental conditions.
  • domain assumption The Raman-noise model and source characterization in supplementary sections V-VII correctly describe noise scaling with fiber attenuation and launched classical power.
    The >200 km / >135 kbps projection (Fig. 5) depends on this model, which is not fully specified in the main text; the residual-gas Raman contribution is explicitly left unquantified (Appendix A.1).
  • standard math Classical capacity 2.3 Tbps estimated via Shannon's formula with the stated received power and bandwidth is representative of the actual data-carrying capability of the bidirectional classical channels.
    Capacity claim is a theoretical upper bound; the experiment itself did not transmit 2.3 Tbps of data.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Entanglement-based quantum key distribution with data in hollow-core fiber." pith.science (2026). https://pith.science/paper/6C6XJCRA

@misc{pith2026260725331,
  author       = {Pith},
  title        = {Pith review of: Entanglement-based quantum key distribution with data in hollow-core fiber},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/6C6XJCRA}},
  note         = {Machine review of arXiv:2607.25331}
}
read the original abstract

The coexistence of quantum information and classical signals in a single fiber is essential for future quantum networks that leverage the well-established optical fiber infrastructure. Although multiplexing technologies can separate quantum and classical signals, pure silica core fibers (PSCFs) remain fundamentally limited by the high nonlinearity, which generates substantial Raman scattering and four-wave mixing noise. Hollow-core fibers (HCFs), guiding light predominantly in air, offer an attractive solution with intrinsically ultra-low nonlinearity and strongly suppressed nonlinear noise. In this work, we demonstrate the entanglement-based key coexisting with data over an 18-km HCF link. We achieve time-encoded high-dimensional quantum key distribution (HD-QKD) carrying 0 dBm of bidirectional received power, corresponding to a theoretical data capacity of up to 2.3 Tbps. During 24 hours of continuous operation, an average secret key rate (SKR) of 10.56 kbps is obtained. Theoretical analysis further predicts SKRs above 135 kbps over transmission distances exceeding 200 km using state-of-the-art low-loss HCFs. These results show significantly improved performance compared with PSCF-based systems and highlight the potential of HCFs for scalable quantum-classical coexistence compatible with the architectures of established fiber-optic networks.

Figures

Figures reproduced from arXiv: 2607.25331 by the authors.

Figure 1
Figure 1. FIG. 1. Performance comparison between SMF and HCF for quantum-classical coexistence. (a) SEM image of HCF in this [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2. Characterization of HCF-based coexistence system. (a) Schematic of system noise measurement. (b) Single-side count [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3. Experimental demonstration of HD-QKD under quantum-classical coexistence conditions. (a) Conceptual illustration [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figures from the paper (2 more)
Figure 4
Figure 4. Figure 4: FIG. 4. Long-term stability test of the HD-QKD system over 24 hours under quantum-classical coexistence conditions. (a) [PITH_FULL_IMAGE:figures/full_fig_p005_4.png]
Figure 5
Figure 5. Figure 5: FIG. 5. Simulated HD-QKD performance on the fiber link length. (a) SKR. (b) PIE. Curves are shown for the simulated [PITH_FULL_IMAGE:figures/full_fig_p007_5.png]

Discussion (0). Sign in to comment.

Reference graph

Works this paper leans on

53 extracted references

  1. [1]

    Hence, trace gases likeO 2,CO 2 and water vapor appear in HCF, whileN 2 is the dominate gas component

    Residual gas composition in the hollow core During fabrication, HCF and its preform was filled with high-purityN 2 gas, and after fabrication, ambient air was pushed into HCF as the as-drawn HCF maintain a sub-atmosphere pressure of 0.2 bar. Hence, trace gases likeO 2,CO 2 and water vapor appear in HCF, whileN 2 is the dominate gas component. Since the op...

  2. [2]

    For Raman spectra characterizations, a tunable continuous-wave (CW) laser was scanned from 196.5 THz (1525.661 nm) to 185.1 THz (1619.624 nm) with a step of 0.1 THz

    Attenuation and Raman spectra characterizations A broadband light source with a wavelength range from 1525 nm to 1620 nm and a total output power of 10 dBm was used together with an OSA with a resolution of 0.02 nm to characterize the attenuation spectra of the HCF and SMF. For Raman spectra characterizations, a tunable continuous-wave (CW) laser was scan...

  3. [3]

    SMF 30.2 -18 – 95.5±0.2 – –

  4. [4]

    SMF 100 -41 – 81±2 – –

  5. [5]

    A. A. E. Hajomer, I. Derkach, V. C. Usenko, U. L. Ander- sen, and T. Gehring, Coexistence of continuous-variable quantum key distribution and classical data over 120 km fiber, Physical Review Letters135, 170804 (2025)

    2025

  6. [6]

    K. A. Patel, J. F. Dynes, I. Choi, A. W. Sharpe, A. R. Dixon, Z. L. Yuan, R. V. Penty, and A. J. Shields, Coexis- tence of high-bit-rate quantum key distribution and data on optical fiber, Physical Review X2, 041010 (2012)

    2012

  7. [7]

    J. Wang, B. J. Rollick, Z.-S. Jia, and B. A. Huberman, Time-interleaved C-band co-propagation of quantum and classical channels, Journal of Lightwave Technology42, 4086 (2024)

    2024

  8. [8]

    Kong, Y.-M

    W.-W. Kong, Y.-M. Sun, Y.-X. Gao, and Y.-F. Ji, Coex- istence of quantum key distribution and optical commu- nication with amplifiers over multicore fiber, Nanopho- tonics12, 1979 (2023)

    1979

Show all 53 references
  1. [9]

    L. Yu, L. Zhang, L. Liu, Z.-C. Jin, J.-L. Wang, H.-Y. Song, W.-J. Ding, F.-X. Wang, W. Chen, Z.-F. Han, and Y.-Z. Gui, Coexistence of optical frequency trans- mission with quantum key distribution over multi-core media, Journal of Lightwave Technology44, 2256 (2026)

    2026

  2. [10]

    Wehner, D

    S. Wehner, D. Elkouss, and R. Hanson, Quantum inter- net: A vision for the road ahead, Science362, eaam9288 (2018)

    2018

  3. [11]

    N. H. Valencia, A. Ma, S. Goel, S. Leedumrong- watthanakun, F. Graffitti, A. Fedrizzi, W. McCutcheon, and M. Malik, A large-scale reconfigurable multiplexed quantum photonic network, Nature Photonics20, 202 (2026)

    2026

  4. [12]

    J. M. Thomas, F. I. Yeh, J. H. Chen, J. J. Mambretti, S. J. Kohlert, G. S. Kanter, and P. Kumar, Quantum teleportation coexisting with classical communications in optical fiber, Optica11, 1700 (2024)

    2024

  5. [13]

    Rahmouni, P

    A. Rahmouni, P. Kuo, Y.-S. Li-Baboud, I. Burenkov, Y. Shi, M. Jabir, N. Lal, D. Reddy, M. Merzouki, L. Ma, et al., 100-km entanglement distribution with coexisting quantum and classical signals in a single fiber, Journal of Optical Communications and Networking16, 781 (2024)

    2024

  6. [14]

    F. Honz, F. Prawits, O. Alia, H. Sakr, T. Bradley, C. Zhang, R. Slav ´ ık, F. Poletti, G. Kanellos, R. Neja- bati,et al., First demonstration of 25λ×10 Gb/s C + L band classical/DV-QKD co-existence over single bidi- rectional fiber link, Journal of Lightwave Technology41, 3587 (2023)

    2023

  7. [15]

    S. Liu, Y. Luo, D. Ge, Y.-R. Fan, H. Li, L.-X. You, D. Wang, D.-C. Zhang, H. Li, G.-C. Guo,et al., Quan- tum entanglement distribution coexisting with classical communication over 18-km hollow-core fibre links, in 2025 European Conference on Optical Communications (ECOC)(IEEE,...

    2025

  8. [16]

    P. Li, G. Chen, A. Jia, H. Li, J. Chu, Y. Liu, L. Zhang, L. Zhang, and J. Luo, Low intermodal interference and low loss hollow core fibers, inOptical Fiber Communi- cation Conference(Optica Publishing Group, 2026) pp. M2J–1

    2026

  9. [17]

    S.-F. Gao, H. Chen, Y.-F. Xiong, Y.-Z. Sun, W. Ding, and Y.-Y. Wang, 40 km, 0.052 dB/km and 83 km, 0.076 dB/km in interstitial-tube-assisted hollow-core fibre, in 2025 European Conference on Optical Communications (ECOC)(IEEE, 2025) pp. 1–4

    2025

  10. [18]

    S. Sato, Y. Kawaguchi, H. Sakuma, T. Haruna, and T. Hasegawa, Record low loss optical fiber with 0.1397 dB/km, in2024 Optical Fiber Communications Confer- ence and Exhibition (OFC)(IEEE, 2024) pp. 1–3

    2024

  11. [19]

    Ferreira da Silva, G

    T. Ferreira da Silva, G. B. Xavier, G. P. Tempor˜ ao, and J. P. von der Weid, Impact of Raman scattered noise from multiple telecom channels on fiber-optic quantum key distribution systems, Journal of Lightwave Technol- ogy32, 2332 (2014)

    2014

  12. [20]

    Dou, R.-D

    T.-Q. Dou, R.-D. Liu, S.-K. Liao, J.-J. Tang, J.-G. Tong, R. Ma, Y.-X. Wan, R.-C. Wang, J. Wu, X.-L. Zhang, Z.- J. Pan, Y. Li, C.-L. Zhang, and S.-B. Tang, Coexistence of 11 Tbps (110×100 Gbps) classical optical communica- tion and quantum key distribution based on single-mode...

    2024

  13. [21]

    HCF 11.5 -17.46 b 2(1) 90.0±0.8 5.4 0.005 c

  14. [22]

    M. R. Dibaj, P. Mehdizadeh, H. Beyranvand, and F. Arpanaei, Traffic-aware trusted node placement and resource allocation in multi-band EONs secured with QKD, Journal of Lightwave Technology43, 6 (2024)

    2024

  15. [23]

    Numkam Fokoua, S

    E. Numkam Fokoua, S. Abokhamis Mousavi, G. T. Ja- sion, D. J. Richardson, and F. Poletti, Loss in hollow-core optical fibers: mechanisms, scaling rules, and limits, Ad- 9 vances in Optics and Photonics15, 1 (2023)

    2023

  16. [24]

    Ding and Y.-Y

    W. Ding and Y.-Y. Wang, Analytic model for light guid- ance in single-wall hollow-core anti-resonant fibers, Op- tics Express22, 27242 (2014)

    2014

  17. [25]

    Wang and W

    Y.-Y. Wang and W. Ding, Confinement loss in hollow- core negative curvature fiber: A multi-layered model, Optics Express25, 33122 (2017)

    2017

  18. [26]

    H. J. Kimble, The quantum internet, Nature453, 1023 (2008)

    2008

  19. [27]

    Eraerds, N

    P. Eraerds, N. Walenta, M. Legr´ e, N. Gisin, and H. Zbinden, Quantum key distribution and 1 Gbps data encryption over a single fibre, New Journal of Physics12, 063027 (2010)

    2010

  20. [28]

    Nasti, H

    U. Nasti, H. Sakr, I. A. Davidson, F. Poletti, and R. J. Donaldson, Utilizing broadband wavelength- division multiplexing capabilities of hollow-core fiber for quantum communications, Applied Optics61, 8959 (2022)

    2022

  21. [29]

    O. Alia, R. S. Tessinari, S. Bahrani, T. D. Bradley, H. Sakr, K. Harrington, J. Hayes, Y. Chen, P. Petropou- los, D. Richardson,et al., DV-QKD coexistence with 1.6 Tbps classical channels over hollow core fibre, Journal of Lightwave Technology40, 5522 (2022)

    2022

  22. [30]

    M. J. Clark, O. Alia, S. Bahrani, G. T. Jasion, H. Sakr, P. Petropoulos, F. Poletti, G. T. Kanellos, J. Rarity, R. Nejabati,et al., Coexistence of entanglement-based quantum channels with dwdm classical channels over hol- low core fibre in a four node quantum communication net...

    2025

  23. [31]

    Kong, T.-Q

    W.-W. Kong, T.-Q. Dou, L. Zhang, P. Li, Z.-H. Li, L.-P. Feng, N. Lu, X.-W. Kan, Y.-M. Sun, J.-J. Tang, and S.-B. Tang, Experimental coexistence of quantum key distribu- tion and high-power classical communication over 101.6 km hollow-core fiber, Journal of Optical Communicatio...

    2025

  24. [32]

    Poggiolini and F

    P. Poggiolini and F. Poletti, Opportunities and challenges for long-distance transmission in hollow-core fibres, Jour- nal of Lightwave Technology40, 1605 (2022)

    2022

  25. [33]

    SMF 50 -19.2 4+2(2+1) e – – 0.007

  26. [34]

    Zhong, H.-C

    T. Zhong, H.-C. Zhou, R. D. Horansky, C. Lee, V. B. Verma, A. E. Lita, A. Restelli, J. C. Bienfang, R. P. Mirin, T. Gerrits,et al., Photon-efficient quantum key distribution using time-energy entanglement with high- dimensional encoding, New Journal of Physics17, 022002 (2015)

    2015

  27. [35]

    SMF 40 -27 2(1) 84.85±2.07 8.61 0.343

  28. [36]

    SMF 45.6 -2.32 d – 74 – –

  29. [37]

    b This power corresponds to the output power at the fiber end, excluding the insertion losses of subsequent filtering and isolation components

    SMF 40 -24 2(1) 84.54±0.72 8.09 1.89 HCF 100 10 4(2) 86.12 12.19 189.7 HCF 100 0 8(3) 93.05 11.50 681.2 Theoreticalf HCF 200 0 8(3) 90.25 15.08 134.7 SMF 40 -24 8(3) 91.68 13.32 235.9 SMF 65 -24 4(2) 81.55 15.58 2.498 aThe entries withd= 2 correspond to implementations based o...

    1992

  30. [38]

    X. Liu, X. Yao, H.-Q. Wang, H. Li, Z. Wang, L.-X. You, Y.-D. Huang, and W. Zhang, Energy-time entanglement- based dispersive optics quantum key distribution over op- tical fibers of 20 km, Applied Physics Letters114, 141104 (2019)

    2019

  31. [39]

    Liu, Z.-H

    J.-Y. Liu, Z.-H. Lin, D.-N. Liu, X. Feng, F. Liu, K.- Y. Cui, Y.-D. Huang, and W. Zhang, High-dimensional quantum key distribution using energy-time entangle- ment over 242 km partially deployed fiber, Quantum Sci- ence and Technology9, 015003 (2024)

    2024

  32. [40]

    Zeng, H.-Y

    P. Zeng, H.-Y. Zhou, W.-J. Wu, and X.-F. Ma, Mode- pairing quantum key distribution, Nature Communica- tions13, 3903 (2022)

    2022

  33. [41]

    Zhu, Y.-Z

    H.-T. Zhu, Y.-Z. Huang, H. Liu, P. Zeng, M. Zou, Y.-Q. Dai, S.-B. Tang, H. Li, L.-X. You, Z. Wang,et al., Exper- imental mode-pairing measurement-device-independent quantum key distribution without global phase locking, Physical Review Letters130, 030801 (2023)

    2023

  34. [42]

    H. Yu, S. Sciara, M. Chemnitz, N. Montaut, B. Crockett, B. Fischer, R. Helsten, B. Wetzel, T. A. Goebel, R. G. Kr¨ amer,et al., Quantum key distribution implemented with d-level time-bin entangled photons, Nature Commu- nications16, 171 (2025)

    2025

  35. [43]

    Zhong, X.-H

    Z.-Q. Zhong, X.-H. Zhan, J.-L. Chen, S. Wang, Z.-Q. Yin, J.-Q. Geng, D.-Y. He, W. Chen, G.-C. Guo, and Z.-F. Han, Hyperentanglement quantum communication over a 50 km noisy fiber channel, Optica11, 1056 (2024)

    2024

  36. [44]

    Y.-R. Fan, Y. Luo, Z.-C. Zhang, Y.-B. Li, S. Liu, D. Wang, D.-C. Zhang, G.-W. Deng, Y. Wang, H.-Z. Song,et al., Energy-time entanglement coexisting with fiber-optical communication in the telecom c band, Phys- ical Review A108, L020601 (2023)

    2023

  37. [45]

    X. Jing, C. Qian, X. Zheng, H. Nian, C. Wang, J. Tang, X. Gu, Y. Kong, T. Chen, Y. Liu,et al., Coexistence of multiuser entanglement distribution and classical light in optical fiber network with a semiconductor chip, Chip3, 100083 (2024)

    2024

  38. [46]

    Luo, Y.-R

    Y. Luo, Y.-R. Fan, K. Guo, J.-T. Zhang, H. Li, G.-W. Deng, Y. Wang, H.-Z. Song, L.-X. You, G.-C. Guo,et al., Quantum entanglement in the C band coexisting with data transmission in the L band, Physical Review A112, 062602 (2025)

    2025

  39. [47]

    C. H. Bennett, G. Brassard, and N. D. Mermin, Quantum cryptography without Bell’s theorem, Physical Review Letters68, 557 (1992)

    1992

  40. [48]

    Michieletto, J

    M. Michieletto, J. K. Lyngsø, C. Jakobsen, J. Lægsgaard, O. Bang, and T. T. Alkeskjold, Hollow-core fibers for high power pulse delivery, Optics Express24, 7103 (2016)

    2016

  41. [49]

    Niu, Y.-M

    J.-N. Niu, Y.-M. Sun, C. Cai, and Y.-F. Ji, Optimized channel allocation scheme for jointly reducing four-wave mixing and Raman scattering in the DWDM-QKD sys- tem, Applied Optics57, 7987 (2018)

    2018

  42. [50]

    Q. Wu, D. Ribezzo, G. Di Sciullo, S. Cocchi, D. Ann Shaji, L. Alves Zischler, R. Luis, P. Serena, C. Lasagni, A. Bononi,et al., Integration of quantum key distribution and high-throughput classical communi- cations in field-deployed multi-core fibers, Light: Science & Applicat...

    2025

  43. [51]

    Shen, C.-Z

    S. Shen, C.-Z. Yuan, Z.-C. Zhang, H. Yu, R.-M. Zhang, C.-R. Yang, H. Li, Z. Wang, Y. Wang, G.-W. Deng,et al., Hertz-rate metropolitan quantum teleportation, Light: Science & Applications12, 115 (2023)

    2023

  44. [52]

    Gavignet, E

    P. Gavignet, E. Pincemin, F. Herviou, Y. Loussouarn, F. Mondain, A. Grant, L. Johnson, R. I. Woodward, J. F. Dynes, B. Summers,et al., Co-propagation of QKD & 6 Tb/s (60×100G) DWDM channels with∼17 dBm to- tal WDM power in single and multi-span configurations, Journal of Light...

    2023

  45. [53]

    M. Y. Niu, F.-H. Xu, J. H. Shapiro, and F. Furrer, Finite- key analysis for time-energy high-dimensional quantum key distribution, Physical Review A94, 052323 (2016)

    2016

Pith tools

Reviewed August 1, 2026 · model on record in the stance chip above.