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

Optics Letters

SNR analysis of a multi-channel temporal correlation scheme in quantum-enhanced target detection

Weihao Wang, Jun Li, Rongyu Wei, Jihong Guo, Qinghua Guo

Published Sep 3, 2024• 0 citations
Publisher

Abstract

In lossy and noisy environments, quantum-enhanced target detection based on temporal quantum correlation encounters low signal-to-noise ratio (SNR), resulting in poor detection performance. To address these challenges, we propose a multi-channel temporal correlation scheme. In this scheme, signal photons from multiple independent entangled sources illuminate the target and arrive at the same detector. Coincidences are obtained by correlation measurements of the entangled photons on one signal path and different reference paths. We then propose a weighted average processing method for fusing the coincidences to obtain higher SNR. The relationship between the SNR and the number of sources is analyzed for different background noise levels. It is shown that the SNR increases as the number of sources increases, but eventually approaches a limit. Experimental results verify the correction of our theoretical analysis.

DOI
10.1364/ol.534868

Related papers

Quantum correlation detection based on compact array

Kun Li, Yuxuan Wang, Wenai Men +1 more

In conventional microwave quantum detection systems, single-photon detection suffers from low signal-to-noise ratio (SNR), requiring extremely high receiver sensitivity that should make the detection system work in low-temperature environment. Although multi-photon accumulation can improve system performance, conventional multi-photon accumulation techniques provide limited SNR enhancement. To address this challenge, a quantum correlation detection based on compact array configuration is proposed. Two identical receiving units combined with correlation processing is exploited to enhance SNR effectively. Firstly, a target detection model using the compact array is established. Subsequently, the signal processing procedure for correlation detection is mathematically derived, with detailed analysis of the relationship between accumulated photon number and SNR. Finally, the effectiveness of the methodology is validated through comprehensive simulations, demonstrating superior performance compared to conventional techniques.

•Aug 8, 2025•0 citations

Target Detection Aided by Quantum Temporal Correlations: Theoretical Analysis and Experimental Validation

Han Liu, Bhashyam Balaji, Amr Saher Helmy

The detection of objects in the presence of significant background noise is a problem of fundamental interest in sensing. In this work, we theoretically analyze a prototype target detection protocol, the quantum temporal correlation (QTC) detection protocol, which is implemented in this work utilizing spontaneous parametric down-converted photon-pair sources. The QTC detection protocol only requires time-resolved photon-counting detection, which is phase-insensitive and therefore suitable for optical target detection. As a comparison to the QTC detection protocol, we also consider a classical phase-insensitive target detection protocol based on intensity detection that is practical in the optical regime. We formulated the target detection problem as a total probe photon transmission estimation problem and obtain an analytical expression of the receiver operating characteristic (ROC) curves. We carry out experiments using a semiconductor waveguide source, which we developed and previously reported. The experimental results agree very well with the theoretical prediction. In particular, we find that in a high-level environment noise and loss, the QTC detection protocol can achieve performance comparable to that of the classical protocol (that is practical in the optical regime) but with \(\simeq 57\) times lower detection time in terms of ROC curve metric. The performance of the QTC detection protocol experiment setup could be further improved with a higher transmission of the reference photon and better detector time uncertainty. Furthermore, the probe photons in the QTC detection protocol are completely indistinguishable from the background noise and therefore useful for covert ranging applications. Finally, our technological platform is highly scalable as well as tunable and thus amenable to large scale integration, which is necessary for practical applications.

arXiv:2004.06765•IEEE Transactions on Aerospace and Electronic Systems•Feb 14, 2020•20 citations

Quantum-enhanced standoff detection using correlated photon pairs

Duncan G. England, Bhashyam Balaji, Benjamin Sussman

We investigate the use of correlated photon pair sources for the improved quantum-level detection of a target in the presence of a noise background. Photon pairs are generated by spontaneous four-wave mixing, one photon from each pair (the herald) is measured locally while the other (the signal) is sent to illuminate the target. Following diffuse reflection from the target, the signal photons are detected by a receiver and nonclassical timing correlations between the signal and herald are measured in the presence of a configurable background noise source. Quantum correlations from the photon pair source can be used to provide an enhanced signal-to-noise ratio when compared to a classical light source of the same intensity.

arXiv:1811.04113•Physical Review A•Feb 19, 2019•139 citations

Performance analysis of Gaussian entangled quantum illumination target detection

Shilong Xu, Yihua Hu, Wuhu Lei

Quantum illumination makes use of the strong correlation between entangled photons, making it possible to detect targets that break through physical limits. The Gaussian entangled state is a continuous variable entangled state with a high number of Hilbert spatial modes, which is currently a viable alternative to quantum lighting. In order to explore the target detection ability of Gaussian entangled state, this paper starts from the Gaussian entanglement model of Lloyd, establishes the target detection error probability boundary model under Gaussian entangled quantum illumination, and explores the optimal detection condition of Gaussian entangled state based on the detection signal-to-noise ratio and the number of measurements. The results show that when the Gaussian entangled state is optimal for the coherent state, the number of measurements is inversely proportional to the signal-to-noise ratio. Under the same error probability, the difference between the detection distances of the two states is determined by the atmospheric attenuation coefficient. The smaller the attenuation coefficient is, the smaller the attenuation coefficient is, the difference is greater.

Applied Optics and Photonics China (AOPC): Optoelectronics and Nanophotonics•Nov 5, 2020•0 citations

Quantum illumination assistant with error-correcting codes

Wen-Zhao Zhang, Yuhan Ma, Jin-Fu Chen +1 more

Abstract We scheme how to enhance the detection ability of quantum target recognition without using entanglement resources. Based on the commonly used error-correcting codes and corresponding decoding method, our scheme gives lower error probability and higher signal-to-noise ratio (SNR) in comparison with the conventional entanglement protocols. In addition, we further investigate the interplay between the SNR and the detection efficiency in quantum target recognition. Results show that, they behave a completely reverse trend when increasing the auxiliary dimension. This is an important limiting factor when optimizing the detection process. Under the existing experimental conditions, our protocol has stronger ability to resist environmental noise when keeping a certain SNR and detection efficiency. Our scheme provides a potential platform for further research and implementation of quantum target recognition.

New Journal of Physics•Dec 11, 2019•6 citations

Enhanced quantum illumination of a lossy target: A sequential interaction model

Shilpi Srivastava, Shubhrangshu Dasgupta

Quantum illumination (QI) exploits quantum correlations to detect weakly reflecting targets embedded in noisy environments with higher sensitivity than classical illumination (CI). We investigate the effectiveness of QI in a realistic setting in which the signal sequentially interacts with a noisy environment and a lossy target. The target is considered at a temperature distinct from its surroundings, while both the interactions are modeled as an action of independent beam splitters with different reflectivities. The detection performance is quantified using the signal-to-noise ratio (SNR) and the quantum Chernoff bound (QCB), the latter providing an upper bound on the error probability. The performance of the Gaussian two-mode squeezed state (TMSS) is compared with that of the optimal classical protocol based on coherent states (CS). The proposed model shows that TMSS consistently achieves a higher SNR than CS for a low-reflectivity target and an arbitrary phase change and remains robust against thermal noise. Furthermore, a sufficiently lower QCB is obtained for TMSS than in previously reported results, indicating greater distinguishability between the presence and absence of the target. These findings underscore the role of realistic modeling in improving QI-based detection of lossy targets, with potential relevance to quantum radar and lidar systems.

quant-pharXiv:2604.12381•Apr 15, 2026•0 citations
In lossy and noisy environments, quantum-enhanced target detection based on temporal quantum correlation encounters low signal-to-noise ratio (SNR), resulting in poor detection performance. To address these challenges, we propose a multi-channel temporal correlation scheme. In this scheme, signal photons from multiple independent entangled sources illuminate the target and arrive at the same detector. Coincidences are obtained by correlation measurements of the entangled photons on one signal path and different reference paths. We then propose a weighted average processing method for fusing the coincidences to obtain higher SNR. The relationship between the SNR and the number of sources is analyzed for different background noise levels. It is shown that the SNR increases as the number of sources increases, but eventually approaches a limit. Experimental results verify the correction of our theoretical analysis.
In conventional microwave quantum detection systems, single-photon detection suffers from low signal-to-noise ratio (SNR), requiring extremely high receiver sensitivity that should make the detection system work in low-temperature environment. Although multi-photon accumulation can improve system performance, conventional multi-photon accumulation techniques provide limited SNR enhancement. To address this challenge, a quantum correlation detection based on compact array configuration is proposed. Two identical receiving units combined with correlation processing is exploited to enhance SNR effectively. Firstly, a target detection model using the compact array is established. Subsequently, the signal processing procedure for correlation detection is mathematically derived, with detailed analysis of the relationship between accumulated photon number and SNR. Finally, the effectiveness of the methodology is validated through comprehensive simulations, demonstrating superior performance compared to conventional techniques.
The detection of objects in the presence of significant background noise is a problem of fundamental interest in sensing. In this work, we theoretically analyze a prototype target detection protocol, the quantum temporal correlation (QTC) detection protocol, which is implemented in this work utilizing spontaneous parametric down-converted photon-pair sources. The QTC detection protocol only requires time-resolved photon-counting detection, which is phase-insensitive and therefore suitable for optical target detection. As a comparison to the QTC detection protocol, we also consider a classical phase-insensitive target detection protocol based on intensity detection that is practical in the optical regime. We formulated the target detection problem as a total probe photon transmission estimation problem and obtain an analytical expression of the receiver operating characteristic (ROC) curves. We carry out experiments using a semiconductor waveguide source, which we developed and previously reported. The experimental results agree very well with the theoretical prediction. In particular, we find that in a high-level environment noise and loss, the QTC detection protocol can achieve performance comparable to that of the classical protocol (that is practical in the optical regime) but with ≃57\simeq 57≃57 times lower detection time in terms of ROC curve metric. The performance of the QTC detection protocol experiment setup could be further improved with a higher transmission of the reference photon and better detector time uncertainty. Furthermore, the probe photons in the QTC detection protocol are completely indistinguishable from the background noise and therefore useful for covert ranging applications. Finally, our technological platform is highly scalable as well as tunable and thus amenable to large scale integration, which is necessary for practical applications.
We investigate the use of correlated photon pair sources for the improved quantum-level detection of a target in the presence of a noise background. Photon pairs are generated by spontaneous four-wave mixing, one photon from each pair (the herald) is measured locally while the other (the signal) is sent to illuminate the target. Following diffuse reflection from the target, the signal photons are detected by a receiver and nonclassical timing correlations between the signal and herald are measured in the presence of a configurable background noise source. Quantum correlations from the photon pair source can be used to provide an enhanced signal-to-noise ratio when compared to a classical light source of the same intensity.
Quantum illumination makes use of the strong correlation between entangled photons, making it possible to detect targets that break through physical limits. The Gaussian entangled state is a continuous variable entangled state with a high number of Hilbert spatial modes, which is currently a viable alternative to quantum lighting. In order to explore the target detection ability of Gaussian entangled state, this paper starts from the Gaussian entanglement model of Lloyd, establishes the target detection error probability boundary model under Gaussian entangled quantum illumination, and explores the optimal detection condition of Gaussian entangled state based on the detection signal-to-noise ratio and the number of measurements. The results show that when the Gaussian entangled state is optimal for the coherent state, the number of measurements is inversely proportional to the signal-to-noise ratio. Under the same error probability, the difference between the detection distances of the two states is determined by the atmospheric attenuation coefficient. The smaller the attenuation coefficient is, the smaller the attenuation coefficient is, the difference is greater.
Abstract We scheme how to enhance the detection ability of quantum target recognition without using entanglement resources. Based on the commonly used error-correcting codes and corresponding decoding method, our scheme gives lower error probability and higher signal-to-noise ratio (SNR) in comparison with the conventional entanglement protocols. In addition, we further investigate the interplay between the SNR and the detection efficiency in quantum target recognition. Results show that, they behave a completely reverse trend when increasing the auxiliary dimension. This is an important limiting factor when optimizing the detection process. Under the existing experimental conditions, our protocol has stronger ability to resist environmental noise when keeping a certain SNR and detection efficiency. Our scheme provides a potential platform for further research and implementation of quantum target recognition.
Quantum illumination (QI) exploits quantum correlations to detect weakly reflecting targets embedded in noisy environments with higher sensitivity than classical illumination (CI). We investigate the effectiveness of QI in a realistic setting in which the signal sequentially interacts with a noisy environment and a lossy target. The target is considered at a temperature distinct from its surroundings, while both the interactions are modeled as an action of independent beam splitters with different reflectivities. The detection performance is quantified using the signal-to-noise ratio (SNR) and the quantum Chernoff bound (QCB), the latter providing an upper bound on the error probability. The performance of the Gaussian two-mode squeezed state (TMSS) is compared with that of the optimal classical protocol based on coherent states (CS). The proposed model shows that TMSS consistently achieves a higher SNR than CS for a low-reflectivity target and an arbitrary phase change and remains robust against thermal noise. Furthermore, a sufficiently lower QCB is obtained for TMSS than in previously reported results, indicating greater distinguishability between the presence and absence of the target. These findings underscore the role of realistic modeling in improving QI-based detection of lossy targets, with potential relevance to quantum radar and lidar systems.