Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1907.01242 · New Journal of Physics

Intercore spontaneous Raman scattering impact on quantum key distribution in multicore fiber

Chun Cai, Yongmei Sun, Yuefeng Ji

Published Jun 25, 2020• 34 citations
arXivHTMLPDF

Abstract

Abstract We propose a theoretical model to quantitatively estimate the intercore spontaneous Raman scattering (ICSRS) in multicore fiber based on intercore crosstalk. We analyze the properties of ICSRS through numerical simulations. Then, the impact of ICSRS on quantum key distribution (QKD) is evaluated with a classical dense wavelength division multiplexing system in a seven-core fiber. We evaluate the impact in two scenarios, long-distance transmission and metropolitan area transmission. For long-distance transmission, it is revealed that both the forward-ICSRS and backward-ICSRS will reduce the maximum transmission distance of QKD and backward-ICSRS has more impairment to QKD. However, over the range of metropolitan area networks, QKD is not impaired seriously by ICSRS with typical power of classical signal. Finally, we compare the properties of SRS generated in single-core fiber and the properties of ICSRS.

DOI
10.1088/1367-2630/aba023

Related papers

Experimental wavelength-space division multiplexing of quantum key distribution with classical optical communication over multicore fiber

Chun Cai, Yongmei Sun, Yongrui Zhang +3 more

We demonstrate quantum key distribution (QKD) with classical signals in a seven-core fiber using dense wavelength division multiplexing. Quantum signals are transmitted in an outer core separately and intercore crosstalk (IC-XT) is the main impairment of them. In order to alleviate IC-XT, we propose a quantum-classical interleave scheme. Then the properties of IC-XT are analyzed based on the measurement results, which indicate counter-propagation is a better co-existence method than co-propagation. Finally, we perform QKD experiments in the presence of two classical channels with a channel spacing of 100 GHz between quantum channel and the nearest classical channels. The experiment results prove counter-propagation almost immune to IC-XT, which is consistent with our analysis. Also, the feasibility of the transmission over the range of metropolitan area networks is validated with our scheme.

arXiv:1811.04198•Optics Express•Feb 11, 2019•53 citations

Impact of Classical Modulation Signals on Quantum Key Distribution Over Multicore Fiber

Weiwen Kong, Yongmei Sun, Chun Cai +1 more

In this paper, the influence of noise induced by classical signals on independent core transmitting quantum key distribution (QKD) is studied over multicore fiber (MCF). We propose a theoretical model of the cascaded noise of spontaneous Raman scattering and inter-core crosstalk (SpRS-ICXT), and the cascaded noise of four-wave mixing and inter-core crosstalk (FWM-ICXT) considering modulation frequency over MCF. To analyze the effect of modulation frequency on QKD, we define and simulate the average power difference and power fluctuation difference of SpRS-ICXT and FWM-ICXT. Then, SpRS-ICXT and FWM-ICXT noises are simulated in two cases: (1) 1 or 3 classical channels and 1 km MCF; (2) 8 or 16 classical channels and 45 km MCF. For the latter case, SpRS-ICXT and FWM-ICXT noises have a serious impact on QKD. Therefore, the impact of noise on QKD is studied. A higher modulation frequency can improve QKD performance, and the secure transmission distance can be further extended by 15.2% when the modulation frequency is 10 GHz relative to ignoring the modulation frequency. However, inter-core crosstalk (ICXT), SpRS-ICXT and FWM-ICXT noises will shorten 52.2% secure transmission distance compared to only transmitting QKD. Finally, the noise of quantum channel is experimentally measured at different symbol rates and modulation formats of classical signals, and it is shown that increasing the symbol rate of data signals at the same optical power degrades the secure key rate of QKD system.

Journal of Lightwave Technology•Apr 6, 2021•27 citations

Multicore fiber-based quantum access network

Chun Cai, Yongmei Sun, Jianing Niu +3 more

We propose a quantum access network based on multicore fiber (MCF) to scale up the number of users in quantum key distribution (QKD) networks. The MCF is used as feeder fiber and single core single mode fibers (SSMFs) are used as drop fibers. Quantum signals (QSs) are integrated with classical signals (CSs) in both MCF and SSMFs to save deployment cost since access networks are cost sensitive. Due to the integration, spontaneous Raman scattering (SRS) and intercore crosstalk (ICXT) are the main impairment sources to QKD. To alleviate the noise, we propose a core and wavelength assignment scheme (CWAS) that a dedicated core of MCF is used to transmit QSs and the wavelengths of QSs are set lower than those of upstream signals. Also, we demonstrate that wavelength time division multiplexing (WTDM) is suitable for QSs which are required to support large number of quantum users, since WTDM can realize higher secure key rate (SKR) than time division multiplexing (TDM) and require lower cost than wavelength division multiplexing (WDM). Finally, the proposed quantum access network is verified experimentally. The experiment results are consistent with our analysis. The properties of SRS in the proposed architecture are shown in the experiments through the quantum bit error rates (QBERs) in different experimental case, which verifies the superiority of the proposed CWAS. Also, the characteristics of the SKRs prove that the number of receivers has a great impact on the performance of QSs using WTDM.

arXiv:1905.05932•May 15, 2019•1 citation

Few-Mode Fiber with Low Spontaneous Raman Scattering for Quantum Key Distribution and Classical Optical Communication Coexistence Systems

Qi Zhao, Jianjun Tang, Weiwen Kong +3 more

In this paper, the theoretical model of spontaneous Raman scattering (SpRS) in few-mode fiber (FMF) is discussed. The influence of SpRS on quantum key distribution (QKD) in FMF is evaluated by combining wavelength division multiplexing (WDM) and space division multiplexing (SDM) techniques. On this basis, an improved ring-assisted FMF is designed and characterized; the transmission distance can be increased by up to 54.5% when choosing different multi-channels. The effects of forward and backward SpRS on QKD are also discussed.

Sensors•Nov 29, 2024•4 citations

Quantum key distribution coexists with classical communication over the nanopore-assisted weakly coupled few-mode fiber

Qi Zhao, Gang Wang, Li Pei +3 more

In this paper, the theoretical model of spontaneous Raman scattering (SpRS) in a few-mode fiber (FMF) is discussed. It evaluates the impact of SpRS on FMF-based quantum key distribution (QKD) by integrating wavelength division multiplexing (WDM) and space division multiplexing (SDM) techniques. To effectively suppress the interference of classical signal-induced noise on quantum signals, we propose a nanopore-assisted FMF, which significantly reduces the complexity of mode coupling and notably enhances the signal transmission distance of the system. Through numerical analysis, the transmission performance of quantum signals under different numbers of wavelengths and channel mode configurations is assessed, with the transmission distance increased by nearly 50% at maximum.

Applied Optics•Jul 22, 2026•0 citations

Coexistence of quantum key distribution and optical communication with amplifiers over multicore fiber

Weiwen Kong, Yongmei Sun, Yaoxian Gao +1 more

In this paper, the influence of classical signals on quantum key distribution (QKD) is studied over multi-core fiber (MCF) when optical amplifiers exist. Firstly, the long-distance simultaneous transmission architectures of QKD and classical signals are proposed based on advanced asymmetric sending or not sending QKD (SNS-QKD) and classical Bennett-Brassard 1984-QKD (BB84-QKD), and the segment length between optical amplifiers can be adjusted according to requirement. Then, theoretical models of spontaneous Raman scattering noise and four-wave mixing noise are established based on the proposed architectures. Next, the calculation models of the secure key rate under the influence of noises from classical signals are derived. Finally, the experimental results show that the theoretical models match well with the experimental photons, and the maximum difference between experimental and simulated noise photons is less than 2.6 dB. Simulation results show that the performance of asymmetric SNS-QKD is better than that of BB84-QKD architecture when classical signals and quantum signals are transmitted in different cores of MCF.

Nanophotonics•Apr 24, 2023•20 citations
Abstract We propose a theoretical model to quantitatively estimate the intercore spontaneous Raman scattering (ICSRS) in multicore fiber based on intercore crosstalk. We analyze the properties of ICSRS through numerical simulations. Then, the impact of ICSRS on quantum key distribution (QKD) is evaluated with a classical dense wavelength division multiplexing system in a seven-core fiber. We evaluate the impact in two scenarios, long-distance transmission and metropolitan area transmission. For long-distance transmission, it is revealed that both the forward-ICSRS and backward-ICSRS will reduce the maximum transmission distance of QKD and backward-ICSRS has more impairment to QKD. However, over the range of metropolitan area networks, QKD is not impaired seriously by ICSRS with typical power of classical signal. Finally, we compare the properties of SRS generated in single-core fiber and the properties of ICSRS.
We demonstrate quantum key distribution (QKD) with classical signals in a seven-core fiber using dense wavelength division multiplexing. Quantum signals are transmitted in an outer core separately and intercore crosstalk (IC-XT) is the main impairment of them. In order to alleviate IC-XT, we propose a quantum-classical interleave scheme. Then the properties of IC-XT are analyzed based on the measurement results, which indicate counter-propagation is a better co-existence method than co-propagation. Finally, we perform QKD experiments in the presence of two classical channels with a channel spacing of 100 GHz between quantum channel and the nearest classical channels. The experiment results prove counter-propagation almost immune to IC-XT, which is consistent with our analysis. Also, the feasibility of the transmission over the range of metropolitan area networks is validated with our scheme.
In this paper, the influence of noise induced by classical signals on independent core transmitting quantum key distribution (QKD) is studied over multicore fiber (MCF). We propose a theoretical model of the cascaded noise of spontaneous Raman scattering and inter-core crosstalk (SpRS-ICXT), and the cascaded noise of four-wave mixing and inter-core crosstalk (FWM-ICXT) considering modulation frequency over MCF. To analyze the effect of modulation frequency on QKD, we define and simulate the average power difference and power fluctuation difference of SpRS-ICXT and FWM-ICXT. Then, SpRS-ICXT and FWM-ICXT noises are simulated in two cases: (1) 1 or 3 classical channels and 1 km MCF; (2) 8 or 16 classical channels and 45 km MCF. For the latter case, SpRS-ICXT and FWM-ICXT noises have a serious impact on QKD. Therefore, the impact of noise on QKD is studied. A higher modulation frequency can improve QKD performance, and the secure transmission distance can be further extended by 15.2% when the modulation frequency is 10 GHz relative to ignoring the modulation frequency. However, inter-core crosstalk (ICXT), SpRS-ICXT and FWM-ICXT noises will shorten 52.2% secure transmission distance compared to only transmitting QKD. Finally, the noise of quantum channel is experimentally measured at different symbol rates and modulation formats of classical signals, and it is shown that increasing the symbol rate of data signals at the same optical power degrades the secure key rate of QKD system.
We propose a quantum access network based on multicore fiber (MCF) to scale up the number of users in quantum key distribution (QKD) networks. The MCF is used as feeder fiber and single core single mode fibers (SSMFs) are used as drop fibers. Quantum signals (QSs) are integrated with classical signals (CSs) in both MCF and SSMFs to save deployment cost since access networks are cost sensitive. Due to the integration, spontaneous Raman scattering (SRS) and intercore crosstalk (ICXT) are the main impairment sources to QKD. To alleviate the noise, we propose a core and wavelength assignment scheme (CWAS) that a dedicated core of MCF is used to transmit QSs and the wavelengths of QSs are set lower than those of upstream signals. Also, we demonstrate that wavelength time division multiplexing (WTDM) is suitable for QSs which are required to support large number of quantum users, since WTDM can realize higher secure key rate (SKR) than time division multiplexing (TDM) and require lower cost than wavelength division multiplexing (WDM). Finally, the proposed quantum access network is verified experimentally. The experiment results are consistent with our analysis. The properties of SRS in the proposed architecture are shown in the experiments through the quantum bit error rates (QBERs) in different experimental case, which verifies the superiority of the proposed CWAS. Also, the characteristics of the SKRs prove that the number of receivers has a great impact on the performance of QSs using WTDM.
In this paper, the theoretical model of spontaneous Raman scattering (SpRS) in few-mode fiber (FMF) is discussed. The influence of SpRS on quantum key distribution (QKD) in FMF is evaluated by combining wavelength division multiplexing (WDM) and space division multiplexing (SDM) techniques. On this basis, an improved ring-assisted FMF is designed and characterized; the transmission distance can be increased by up to 54.5% when choosing different multi-channels. The effects of forward and backward SpRS on QKD are also discussed.
In this paper, the theoretical model of spontaneous Raman scattering (SpRS) in a few-mode fiber (FMF) is discussed. It evaluates the impact of SpRS on FMF-based quantum key distribution (QKD) by integrating wavelength division multiplexing (WDM) and space division multiplexing (SDM) techniques. To effectively suppress the interference of classical signal-induced noise on quantum signals, we propose a nanopore-assisted FMF, which significantly reduces the complexity of mode coupling and notably enhances the signal transmission distance of the system. Through numerical analysis, the transmission performance of quantum signals under different numbers of wavelengths and channel mode configurations is assessed, with the transmission distance increased by nearly 50% at maximum.
In this paper, the influence of classical signals on quantum key distribution (QKD) is studied over multi-core fiber (MCF) when optical amplifiers exist. Firstly, the long-distance simultaneous transmission architectures of QKD and classical signals are proposed based on advanced asymmetric sending or not sending QKD (SNS-QKD) and classical Bennett-Brassard 1984-QKD (BB84-QKD), and the segment length between optical amplifiers can be adjusted according to requirement. Then, theoretical models of spontaneous Raman scattering noise and four-wave mixing noise are established based on the proposed architectures. Next, the calculation models of the secure key rate under the influence of noises from classical signals are derived. Finally, the experimental results show that the theoretical models match well with the experimental photons, and the maximum difference between experimental and simulated noise photons is less than 2.6 dB. Simulation results show that the performance of asymmetric SNS-QKD is better than that of BB84-QKD architecture when classical signals and quantum signals are transmitted in different cores of MCF.