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:2403.14132

Enhancing sensitivity of atomic microwave receiver combining laser arrays

Bo Wu, Ruiqi Mao, Liu, Yi, Di Sang, Zhou, Yanli, Lin, Yi, Qiang An, Yunqi Fu

Published Mar 21, 2024• 0 citations
arXivHTMLPDF

Abstract

Rydberg atom,which exhibits a strong response to weak electric(E) fields,is regarded as a promising atomic receiver to surpass sensitivity of conventional receivers. However, its sensitivity is strongly limited by the noise coming from both classical and quantum levels and how to enhance it significantly remains challenging. Here we experimentally prove that the sensitivity of Rydberg atomic receiver can be increased to 23 nV/cm/Hz1/2 by combining laser arrays. Theoretically, we demonstrate that multiple beams illuminating on a PD perform better than multiple PDs for laser arrays.In our experiment,10 dB SNR enhancement is achieved by utilizing 2 * 2 probe beam arrays, compared to the performance of a laser beam,and it can be enhanced further just by adding a resonator. The results could offer an avenue for the design and optimization of ultrahigh-sensitivity Rydberg atomic receivers and promote applications in cosmology, meteorology, communication, and microwave quantum technology.

DOI
10.48550/arxiv.2403.14132

Related papers

Enhancing Sensitivity of Atomic Microwave Receivers Based on Optimal Laser Arrays

Bo Wu, Ruiqi Mao, Di Sang +5 more

Rydberg atom, which exhibits a strong response to weak electric fields, is regarded as a promising atomic receiver to surpass the sensitivity of conventional receivers. However, its sensitivity is strongly limited by the noise coming from both classical and quantum levels, and how to enhance it significantly remains challenging. In theory, we aim to optimize the laser array, highlighting the importance of coherence among microwave signals and the uniformity of laser beam power within the array, to enhance the signal-to-noise ratio (SNR) and elevate sensitivity to a new standard. To enhance practical application mobility and integration, we propose two optimization schemes: a six-port fiber-coupled vapor cell probe array and cascaded diffraction gratings. We maintain steady MW signal coherence in the laser array by using identical vapor cells and positioning the probe lasers on the incident wave’s equal phase plane. Our findings reveal that the wavefront phase difference for the six-port fiber-coupled vapor cell array is 10°, while the cascaded diffraction gratings show a 16° difference, with laser intensity uniformity reaching 90.4%. In our experiment, a 4.6-dB SNR enhancement was achieved by utilizing the cascaded diffraction gratings to generate$2 \times 2$probe laser arrays compared to the performance of a laser beam, which can be enhanced further just by adding more laser beams. In particular, a$2 \times 2$laser array experimental verification yielded$19~\text {nv/cm}/\sqrt {\textrm {Hz}}$@8.57 GHz. More importantly, the intermediate signals of the laser array maintain coherence. Therefore, SNR improvement is allowed even in detecting weak target signals amid strong noise and clutter. The results could offer an avenue for the design and optimization of ultrahigh-sensitivity Rydberg atomic receivers and promote applications in cosmology, meteorology, communication, and MW quantum technology.

IEEE Transactions on Antennas and Propagation•Oct 31, 2024•34 citations

Impact of beam diameter on sensitivity in Rydberg atomic microwave receiver

Fengting Zhao, Qiang An, Jinhao Zhang +1 more

Quantum microwave measurement techniques based on Rydberg atoms exhibit exceptional potential in microwave communication, sub-wavelength imaging and quantum metrology, due to the inherent advantages of self-calibration, minimal interference with external electric fields, and a broadband range of measurable frequencies. However, the current measurement sensitivity is not yet comparable to that of classical receivers. One contributing factor is the low utilization of atoms within the vapor cell, which remains a significant challenge to enhance substantially. To address this problem, scholars have proposed a variety of optical domain methods to enhance sensitivity. For example, increasing vapor cell length, utilizing multi-photons excitation or repump lasers. Despite these advancements, the study of the influence of laser beam diameter on the sensitivity is insufficient, and the lack of a comprehensive experimental investigation is not conducive to the practical application and optimization of the receiver. In this study, we investigate the impact of varying probe laser diameters on receiver sensitivity using a beam expander to adjust the diameter from 600 μm to 3 mm. Modifying the beam diameter could alter the light-atom interaction area in the vapor cell, offering a feasible approach to adjust the utilization of the atoms. Our findings indicate that under the experimental conditions, the sensitivity could be enhanced by expanding the beam diameter, where the sensitivity is changed from 299 nV cm-1 Hz-1/2 to 127 nV cm-1 Hz-1/2. These results could provide valuable insights for designing and optimizing ultrahigh-sensitivity Rydberg atomic receivers and facilitating applications in meteorology, communication, and quantum precision measurement.

Applied Optics and Photonics China (AOPC)•Oct 28, 2025•0 citations

Cavity-enhanced Rydberg atomic superheterodyne receiver

Yukang Liang, Qinxia Wang, Zhi‐Hui Wang +7 more

High-sensitivity measurements of the microwave electric field are important in applications of communication and metrology. The sensitivity of traditional Rydberg superheterodyne receivers in free space is effectively determined by the signal-to-noise ratio (SNR), which is often considered equivalent to sensitivity in practical sensing applications. In this work, we demonstrate a cavity-enhanced receiver, where an optical cavity significantly amplifies the interaction between the probe light and cesium atoms, which substantially improves the signal-to-noise ratio via enhancing the expansion coefficient κ . Here, κ is the edge slope of the single peak obtained by fitting the double-peak EIT-AT spectrum, characterizing the response of the probe light to the frequency detuning of the coupling laser. The sensitivity is thus boosted by a factor of approximately 19 dB. This study highlights the pivotal role of optical cavities in advancing Rydberg-based detection systems, offering a promising approach for high-sensitivity microwave electric field measurements.

arXiv:2502.20792•Optics Express•Mar 4, 2025•7 citations

Sensitivity Enhancement of S-Band Rydberg Atom Microwave Receiver Using Resonant Cavity

Yipeng Xie, Xinbing Chen, Mingwei Lei +1 more

Rydberg atom-based microwave electric field sensing has attracted growing interest owing to its inherent advantages, such as absolute calibration, wideband operability, and compatibility with room-temperature devices. A critical bottleneck that limits sensitivity is the inefficient coupling between the Rydberg atoms and the incident microwave field, particularly when detecting weak signals propagating in free space. Here we propose and experimentally validate a scheme that integrates a horn antenna with a resonant microwave cavity to significantly improve this coupling for free-space signal reception in the S-band. Using a two-photon excitation scheme in a cesium vapor cell, we systematically characterize the sensing performance under three configurations: a bare cell, direct cavity injection, and a cavity coupled to a horn antenna that captures free-space microwave signals over a 1 m distance. In the antenna-coupled cavity configuration, we achieve an optimal sensitivity of 2.33 nV/cm/$\sqrt{\text{Hz}}$ at the receiving antenna, which corresponds to an enhancement of approximately 17.9 dB compared to the optimized bare vapor cell configuration. Our findings offer a practical and effective route to boost the sensitivity of Rydberg atomic sensors, facilitating their adoption in real-world microwave metrology and wireless communication applications where weak free-space electric fields must be reliably measured.

physics.atom-phCross-listedarXiv:2606.02669•Optics Express•Jun 2, 2026•0 citations

High-Sensitivity Rydberg Atom-Based Field Sensing Enhancement Using Miniaturized Resonator

Aojie Zhou, Yi Lin, Ruiqi Mao +4 more

High-sensitivity amplitude and frequency detection of microwave electric fields is of significant importance in various fields, including communications, microwave quantum technology, aerospace, medicine, and meteorology. Rydberg atom-based sensors promise traceable standards and high sensitivity for detecting weak electric fields and enhancing sensing sensitivity, mainly by using superheterodyne technology and resonant structures. Detecting high-frequency (HF) band fields with high sensitivity using Rydberg atom sensors is a significant challenge due to the requirement of exciting atoms to extremely high energy states for resonant detection. We demonstrate the off-resonant Rydberg atomic superheterodyne architecture with additional resonators for greatly enhancing the sensing sensitivity to HF band fields. In this approach, we propose a miniaturized square spiral resonator with an electrical size of$0.011~\lambda $at 15.54 MHz. To reduce the electric-field-screening effect of the adsorption of alkali metal atoms, we use a monocrystalline sapphire cesium (Cs) vapor cell. By utilizing the off-resonant alternating current (ac) Stark effect, the initial sensitivity of the Rydberg atom sensor without the resonator is measured to be$10.39~\mu \text {V/cm}\sqrt {\text {Hz}}$at room temperature. With the addition of the miniaturized square spiral resonator, the sensitivity significantly improved to$2.60~\text {nV/cm}\sqrt {\text {Hz}}$, which has been inaccessible so far with atomic sensors. Here, we provide an enhancement of 72 dB, which is three orders of magnitude improvement in sensitivity than when the resonator is not used. This enhancement resonator extends Rydberg atomic high-sensitivity sensing to the HF band and shows great potential, especially in shortwave radio reception.

IEEE Transactions on Antennas and Propagation•Aug 13, 2025•9 citations

Enhancing Sensitivity of an Atomic Microwave Receiver via a Fabry-Perot Cavity

Bo Wu, Dunwei Liao, Di Sang +2 more

Rydberg atom-based microwave (MW) atomic receiver is regarded as a promising atomic receiver to surpass the sensitivity of conventional receivers. This article proposes a tunable Fabry-Perot (FP) cavity that locally enhances the MW electric (E) field to improve measurement sensitivities. This FP cavity includes a 0.9947 reflection coefficient periodic metal slit structure and a reflective plate. In our experiment, 21-dB signal-to-noise ratio (SNR) enhancement is achieved by utilizing the FP cavity. Ultimately, the atomic receiver loaded with a FP cavity provides a sensitivity of$ \mathbf {5 \mathbf {nv/cm/\sqrt {Hz}}}$@8.57 GHz that is the most advanced sensitivity known based on$\mathbf {^{133}\textrm {Cs}}$resonant transition$\mathbf {|44D_{5/2}\rangle \rightarrow |45P_{3/2}\rangle }$. Since the FP cavity is different from the traditional closed cavity and split-ring resonance mechanism, a large enhancement tunable frequency bandwidth of 4.8–12.2 GHz can be achieved by adjusting the plate spacing. In addition, the FP cavity solves the direct coupling between the electromagnetic wave and the resonator in the X-band, which provides mobility and flexibility. We take all the vapor cell wall’s refractive index and metal reflections into account as the resonance-based system is more sensitive to errors.

IEEE Transactions on Antennas and Propagation•Oct 21, 2024•34 citations
Rydberg atom,which exhibits a strong response to weak electric(E) fields,is regarded as a promising atomic receiver to surpass sensitivity of conventional receivers. However, its sensitivity is strongly limited by the noise coming from both classical and quantum levels and how to enhance it significantly remains challenging. Here we experimentally prove that the sensitivity of Rydberg atomic receiver can be increased to 23 nV/cm/Hz1/2 by combining laser arrays. Theoretically, we demonstrate that multiple beams illuminating on a PD perform better than multiple PDs for laser arrays.In our experiment,10 dB SNR enhancement is achieved by utilizing 2 * 2 probe beam arrays, compared to the performance of a laser beam,and it can be enhanced further just by adding a resonator. The results could offer an avenue for the design and optimization of ultrahigh-sensitivity Rydberg atomic receivers and promote applications in cosmology, meteorology, communication, and microwave quantum technology.
Rydberg atom, which exhibits a strong response to weak electric fields, is regarded as a promising atomic receiver to surpass the sensitivity of conventional receivers. However, its sensitivity is strongly limited by the noise coming from both classical and quantum levels, and how to enhance it significantly remains challenging. In theory, we aim to optimize the laser array, highlighting the importance of coherence among microwave signals and the uniformity of laser beam power within the array, to enhance the signal-to-noise ratio (SNR) and elevate sensitivity to a new standard. To enhance practical application mobility and integration, we propose two optimization schemes: a six-port fiber-coupled vapor cell probe array and cascaded diffraction gratings. We maintain steady MW signal coherence in the laser array by using identical vapor cells and positioning the probe lasers on the incident wave’s equal phase plane. Our findings reveal that the wavefront phase difference for the six-port fiber-coupled vapor cell array is 10°, while the cascaded diffraction gratings show a 16° difference, with laser intensity uniformity reaching 90.4%. In our experiment, a 4.6-dB SNR enhancement was achieved by utilizing the cascaded diffraction gratings to generate2×22 \times 22×2probe laser arrays compared to the performance of a laser beam, which can be enhanced further just by adding more laser beams. In particular, a2×22 \times 22×2laser array experimental verification yielded19 nv/cm/Hz19~\text {nv/cm}/\sqrt {\textrm {Hz}}19 nv/cm/Hz​@8.57 GHz. More importantly, the intermediate signals of the laser array maintain coherence. Therefore, SNR improvement is allowed even in detecting weak target signals amid strong noise and clutter. The results could offer an avenue for the design and optimization of ultrahigh-sensitivity Rydberg atomic receivers and promote applications in cosmology, meteorology, communication, and MW quantum technology.
Quantum microwave measurement techniques based on Rydberg atoms exhibit exceptional potential in microwave communication, sub-wavelength imaging and quantum metrology, due to the inherent advantages of self-calibration, minimal interference with external electric fields, and a broadband range of measurable frequencies. However, the current measurement sensitivity is not yet comparable to that of classical receivers. One contributing factor is the low utilization of atoms within the vapor cell, which remains a significant challenge to enhance substantially. To address this problem, scholars have proposed a variety of optical domain methods to enhance sensitivity. For example, increasing vapor cell length, utilizing multi-photons excitation or repump lasers. Despite these advancements, the study of the influence of laser beam diameter on the sensitivity is insufficient, and the lack of a comprehensive experimental investigation is not conducive to the practical application and optimization of the receiver. In this study, we investigate the impact of varying probe laser diameters on receiver sensitivity using a beam expander to adjust the diameter from 600 μm to 3 mm. Modifying the beam diameter could alter the light-atom interaction area in the vapor cell, offering a feasible approach to adjust the utilization of the atoms. Our findings indicate that under the experimental conditions, the sensitivity could be enhanced by expanding the beam diameter, where the sensitivity is changed from 299 nV cm-1 Hz-1/2 to 127 nV cm-1 Hz-1/2. These results could provide valuable insights for designing and optimizing ultrahigh-sensitivity Rydberg atomic receivers and facilitating applications in meteorology, communication, and quantum precision measurement.
High-sensitivity measurements of the microwave electric field are important in applications of communication and metrology. The sensitivity of traditional Rydberg superheterodyne receivers in free space is effectively determined by the signal-to-noise ratio (SNR), which is often considered equivalent to sensitivity in practical sensing applications. In this work, we demonstrate a cavity-enhanced receiver, where an optical cavity significantly amplifies the interaction between the probe light and cesium atoms, which substantially improves the signal-to-noise ratio via enhancing the expansion coefficient κ . Here, κ is the edge slope of the single peak obtained by fitting the double-peak EIT-AT spectrum, characterizing the response of the probe light to the frequency detuning of the coupling laser. The sensitivity is thus boosted by a factor of approximately 19 dB. This study highlights the pivotal role of optical cavities in advancing Rydberg-based detection systems, offering a promising approach for high-sensitivity microwave electric field measurements.
Rydberg atom-based microwave electric field sensing has attracted growing interest owing to its inherent advantages, such as absolute calibration, wideband operability, and compatibility with room-temperature devices. A critical bottleneck that limits sensitivity is the inefficient coupling between the Rydberg atoms and the incident microwave field, particularly when detecting weak signals propagating in free space. Here we propose and experimentally validate a scheme that integrates a horn antenna with a resonant microwave cavity to significantly improve this coupling for free-space signal reception in the S-band. Using a two-photon excitation scheme in a cesium vapor cell, we systematically characterize the sensing performance under three configurations: a bare cell, direct cavity injection, and a cavity coupled to a horn antenna that captures free-space microwave signals over a 1 m distance. In the antenna-coupled cavity configuration, we achieve an optimal sensitivity of 2.33 nV/cm/Hz\sqrt{\text{Hz}}Hz​ at the receiving antenna, which corresponds to an enhancement of approximately 17.9 dB compared to the optimized bare vapor cell configuration. Our findings offer a practical and effective route to boost the sensitivity of Rydberg atomic sensors, facilitating their adoption in real-world microwave metrology and wireless communication applications where weak free-space electric fields must be reliably measured.
High-sensitivity amplitude and frequency detection of microwave electric fields is of significant importance in various fields, including communications, microwave quantum technology, aerospace, medicine, and meteorology. Rydberg atom-based sensors promise traceable standards and high sensitivity for detecting weak electric fields and enhancing sensing sensitivity, mainly by using superheterodyne technology and resonant structures. Detecting high-frequency (HF) band fields with high sensitivity using Rydberg atom sensors is a significant challenge due to the requirement of exciting atoms to extremely high energy states for resonant detection. We demonstrate the off-resonant Rydberg atomic superheterodyne architecture with additional resonators for greatly enhancing the sensing sensitivity to HF band fields. In this approach, we propose a miniaturized square spiral resonator with an electrical size of$0.011~\lambda $at 15.54 MHz. To reduce the electric-field-screening effect of the adsorption of alkali metal atoms, we use a monocrystalline sapphire cesium (Cs) vapor cell. By utilizing the off-resonant alternating current (ac) Stark effect, the initial sensitivity of the Rydberg atom sensor without the resonator is measured to be10.39 μV/cmHz10.39~\mu \text {V/cm}\sqrt {\text {Hz}}10.39 μV/cmHz​at room temperature. With the addition of the miniaturized square spiral resonator, the sensitivity significantly improved to2.60 nV/cmHz2.60~\text {nV/cm}\sqrt {\text {Hz}}2.60 nV/cmHz​, which has been inaccessible so far with atomic sensors. Here, we provide an enhancement of 72 dB, which is three orders of magnitude improvement in sensitivity than when the resonator is not used. This enhancement resonator extends Rydberg atomic high-sensitivity sensing to the HF band and shows great potential, especially in shortwave radio reception.
Rydberg atom-based microwave (MW) atomic receiver is regarded as a promising atomic receiver to surpass the sensitivity of conventional receivers. This article proposes a tunable Fabry-Perot (FP) cavity that locally enhances the MW electric (E) field to improve measurement sensitivities. This FP cavity includes a 0.9947 reflection coefficient periodic metal slit structure and a reflective plate. In our experiment, 21-dB signal-to-noise ratio (SNR) enhancement is achieved by utilizing the FP cavity. Ultimately, the atomic receiver loaded with a FP cavity provides a sensitivity of$ \mathbf {5 \mathbf {nv/cm/\sqrt {Hz}}}@8.57GHzthatisthemostadvancedsensitivityknownbasedon@8.57 GHz that is the most advanced sensitivity known based on@8.57GHzthatisthemostadvancedsensitivityknownbasedon\mathbf {^{133}\textrm {Cs}}resonanttransitionresonant transitionresonanttransition\mathbf {|44D_{5/2}\rangle \rightarrow |45P_{3/2}\rangle }$. Since the FP cavity is different from the traditional closed cavity and split-ring resonance mechanism, a large enhancement tunable frequency bandwidth of 4.8–12.2 GHz can be achieved by adjusting the plate spacing. In addition, the FP cavity solves the direct coupling between the electromagnetic wave and the resonator in the X-band, which provides mobility and flexibility. We take all the vapor cell wall’s refractive index and metal reflections into account as the resonance-based system is more sensitive to errors.