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

Quantum-enhanced Optical Beat-note Detection beyond 3-dB Noise Penalty of Image Band

Keitaro Anai, Yutaro Enomoto, H. Omura, Koji Nagano, Kiwamu Izumi, Mamoru Endo, Shuntaro Takeda

Published Jan 1, 2024• 1 citation
Publisher

Abstract

We propose and demonstrate a method to, in principle, completely remove shot noise of optical beat-note detection using squeezed light. This leads to improving the sensitivity of various spatial/temporal measurements.
DOI
10.1364/cleo_at.2024.ath1g.3

Related papers

Quantum-enhanced optical phase-insensitive heterodyne detection beyond 3-dB noise penalty of image band

Keitaro Anai, Yutaro Enomoto, H. Omura +4 more

Optical phase-insensitive heterodyne (beat-note) detection, which measures the relative phase of two beams at different frequencies through their interference, is a key sensing technology for various spatial/temporal measurements, such as frequency measurements in optical frequency combs. However, its sensitivity is limited not only by shot noise from the signal frequency band but also by the extra shot noise from an image band, known as the 3-dB noise penalty. Here, we propose a method to remove shot noise from all these bands using squeezed light. We also demonstrate beyond-3-dB noise reduction experimentally, confirming that our method actually reduces shot noise from both the signal and extra bands simultaneously. Our work should boost the sensitivity of various spatial/temporal measurements beyond the current limitations.

arXiv:2305.06579•Optics Express•May 2, 2024•8 citations

Sub-shot-noise measurements using the beat note between quantum-correlated photon beams

J. J. Snyder, E. Giacobino, M. Ducloy +2 more

We propose a new method for optical measurements below the shot-noise limit. The method is based on detecting the beat note between the two quantum-correlated beams emitted by a nondegenerate optical parametric oscillator operating above threshold. Such a method can be used to enhance the sensitivity of light-scattering and polarization-rotation measurements.

Journal of the Optical Society of America B•Oct 1, 1990•27 citations

Quantum-Enhanced Phase Detection in a Lithium Niobate Photonic Integrated Circuit

Hubert S. Stokowski, Timothy P. McKenna, Tae‐Won Park +6 more

Squeezed light promises improved optical measurement sensitivity. We present a photonic integrated circuit with an embedded squeezed light source. It achieves 4% SNR improvement over shot-noise and paves the way toward deployable quantum optical sensors.

•Jan 1, 2023•0 citations

Mechanism of suppressing noise intensity of squeezed state enhancement

Ruotao ZHANG, Wenhui Zhang

This research focuses on advanced noise suppression technologies for high-precision measurement systems, particularly addressing the limitations of classical noise reducing approaches. The noise level of laser sources is a crucial factor that directly affects the measurement sensitivity in applications such as gravitational wave detection and biomedical imaging. Classical feedback control technologies are effective but often encounter a bottleneck resulting from the classical noise suppression limits. To cope with these challenges, a novel method integrating quantum squeezed light with classical feedback control systems to reduce intensity noise is proposed in this work. By employing an amplitude-squeezed light field, a quantum-enhanced feedback control model is developed, thereby theoretically examining the influence of both the feedback loop gain and the degree of squeezing on the noise suppression performance. The results show that the injection of squeezed light significantly reduces the intensity noise, approaching the shot noise limit (SNL), thereby improving the system sensitivity beyond the classical noise reduction boundaries. Specifically, –10 dB squeezed state injection into the feedback system yields an additional noise suppression of approximately 8.97 dB, exceeding what is achievable using classical feedback alone. This demonstrates that the potential of the proposed method can enhance measurement precision close to the quantum noise limits without increasing the laser power. The analysis highlights the asymmetric noise suppression effects between the inner feedback loop and outer feedback loop. Although the outer loop benefits significantly from the squeezed light injection and achieves noise levels that are unattainable by classical feedback methods, the inner loop shows relatively minor improvements. This asymmetry is attributed to the inherent characteristics of quantum squeezing and the limitations of the feedback loop design. Further investigation into the individual noise components reveals that the primary contributors to the intensity noise include input noise, photodetector noise, and beam splitter-induced vacuum fluctuations. The injection of squeezed light effectively mitigates these vacuum fluctuations, which are typically a major noise source in high-precision laser systems. Theoretical research results show that the use of squeezed light in feedback control systems can effectively enhance noise suppression, equivalent to a nine fold increase in detected optical power, without the physical drawbacks of increasing laser power such as thermal noise. In conclusion, this study provides a theoretical validation of combining quantum squeezed states with classical feedback control to exceed classical noise suppression limits. The integration of a –10 dB squeezed state demonstrates a significant noise reduction, showing that this hybrid approach could revolutionize noise management in precision measurement applications. The results pave the way for further exploring quantum-enhanced control technologies in fields such as gravitational wave detection, quantum communication, and advanced optical sensing, providing a pathway for improving sensitivity and noise suppression without increasing additional power requirements.

Acta Physica Sinica•Jan 1, 2025•1 citation

Overcoming detection loss and noise in squeezing-based optical sensing

Gaetano Frascella, Sascha Agne, Farid Ya. Khalili +1 more

Abstract Among the known resources of quantum metrology, one of the most practical and efficient is squeezing. Squeezed states of atoms and light improve the sensing of the phase, magnetic field, polarization, mechanical displacement. They promise to considerably increase signal-to-noise ratio in imaging and spectroscopy, and are already used in real-life gravitational-wave detectors. But despite being more robust than other states, they are still very fragile, which narrows the scope of their application. In particular, squeezed states are useless in measurements where the detection is inefficient or the noise is high. Here, we experimentally demonstrate a remedy against loss and noise: strong noiseless amplification before detection. This way, we achieve loss-tolerant operation of an interferometer fed with squeezed and coherent light. With only 50% detection efficiency and with noise exceeding the level of squeezed light more than 50 times, we overcome the shot-noise limit by 6 dB. Sub-shot-noise phase sensitivity survives up to 87% loss. Application of this technique to other types of optical sensing and imaging promises a full use of quantum resources in these fields.

arXiv:2005.08843•npj Quantum Information•May 12, 2021•68 citations

Quantum-enhanced stimulated Raman scattering imaging in dual-polarization scheme

Zicong Xu, Kenichi Oguchi, Sho Nitanai +3 more

Benefitting from the sub-Poissonian statistics, squeezed light has been applied to push the shot-noise-limited sensitivity of stimulated Raman scattering spectroscopy and microscopy to a sub-shot-noise level [5]. However, the balanced detection regime requires a high squeezing level to counteract the 3-dB signal-to-noise ratio (SNR) drawback. In this presentation, we introduce dual-polarization quantum-enhanced stimulated Raman scattering (QESRS), which is also suitable for high-power operation [6]. This approach utilizes a symmetric beamsplitter but detects squeezed light on two independent photodetectors, thus avoiding the 3-dB decrease in SNR.

JSAP-OSA Joint Symposia•Jan 1, 2023•0 citations
Optical phase-insensitive heterodyne (beat-note) detection, which measures the relative phase of two beams at different frequencies through their interference, is a key sensing technology for various spatial/temporal measurements, such as frequency measurements in optical frequency combs. However, its sensitivity is limited not only by shot noise from the signal frequency band but also by the extra shot noise from an image band, known as the 3-dB noise penalty. Here, we propose a method to remove shot noise from all these bands using squeezed light. We also demonstrate beyond-3-dB noise reduction experimentally, confirming that our method actually reduces shot noise from both the signal and extra bands simultaneously. Our work should boost the sensitivity of various spatial/temporal measurements beyond the current limitations.
This research focuses on advanced noise suppression technologies for high-precision measurement systems, particularly addressing the limitations of classical noise reducing approaches. The noise level of laser sources is a crucial factor that directly affects the measurement sensitivity in applications such as gravitational wave detection and biomedical imaging. Classical feedback control technologies are effective but often encounter a bottleneck resulting from the classical noise suppression limits. To cope with these challenges, a novel method integrating quantum squeezed light with classical feedback control systems to reduce intensity noise is proposed in this work. By employing an amplitude-squeezed light field, a quantum-enhanced feedback control model is developed, thereby theoretically examining the influence of both the feedback loop gain and the degree of squeezing on the noise suppression performance. The results show that the injection of squeezed light significantly reduces the intensity noise, approaching the shot noise limit (SNL), thereby improving the system sensitivity beyond the classical noise reduction boundaries. Specifically, –10 dB squeezed state injection into the feedback system yields an additional noise suppression of approximately 8.97 dB, exceeding what is achievable using classical feedback alone. This demonstrates that the potential of the proposed method can enhance measurement precision close to the quantum noise limits without increasing the laser power. The analysis highlights the asymmetric noise suppression effects between the inner feedback loop and outer feedback loop. Although the outer loop benefits significantly from the squeezed light injection and achieves noise levels that are unattainable by classical feedback methods, the inner loop shows relatively minor improvements. This asymmetry is attributed to the inherent characteristics of quantum squeezing and the limitations of the feedback loop design. Further investigation into the individual noise components reveals that the primary contributors to the intensity noise include input noise, photodetector noise, and beam splitter-induced vacuum fluctuations. The injection of squeezed light effectively mitigates these vacuum fluctuations, which are typically a major noise source in high-precision laser systems. Theoretical research results show that the use of squeezed light in feedback control systems can effectively enhance noise suppression, equivalent to a nine fold increase in detected optical power, without the physical drawbacks of increasing laser power such as thermal noise. In conclusion, this study provides a theoretical validation of combining quantum squeezed states with classical feedback control to exceed classical noise suppression limits. The integration of a –10 dB squeezed state demonstrates a significant noise reduction, showing that this hybrid approach could revolutionize noise management in precision measurement applications. The results pave the way for further exploring quantum-enhanced control technologies in fields such as gravitational wave detection, quantum communication, and advanced optical sensing, providing a pathway for improving sensitivity and noise suppression without increasing additional power requirements.
Abstract Among the known resources of quantum metrology, one of the most practical and efficient is squeezing. Squeezed states of atoms and light improve the sensing of the phase, magnetic field, polarization, mechanical displacement. They promise to considerably increase signal-to-noise ratio in imaging and spectroscopy, and are already used in real-life gravitational-wave detectors. But despite being more robust than other states, they are still very fragile, which narrows the scope of their application. In particular, squeezed states are useless in measurements where the detection is inefficient or the noise is high. Here, we experimentally demonstrate a remedy against loss and noise: strong noiseless amplification before detection. This way, we achieve loss-tolerant operation of an interferometer fed with squeezed and coherent light. With only 50% detection efficiency and with noise exceeding the level of squeezed light more than 50 times, we overcome the shot-noise limit by 6 dB. Sub-shot-noise phase sensitivity survives up to 87% loss. Application of this technique to other types of optical sensing and imaging promises a full use of quantum resources in these fields.
Benefitting from the sub-Poissonian statistics, squeezed light has been applied to push the shot-noise-limited sensitivity of stimulated Raman scattering spectroscopy and microscopy to a sub-shot-noise level [5]. However, the balanced detection regime requires a high squeezing level to counteract the 3-dB signal-to-noise ratio (SNR) drawback. In this presentation, we introduce dual-polarization quantum-enhanced stimulated Raman scattering (QESRS), which is also suitable for high-power operation [6]. This approach utilizes a symmetric beamsplitter but detects squeezed light on two independent photodetectors, thus avoiding the 3-dB decrease in SNR.