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

Journal of Physics Conference Series

Influence of Cell Temperature on the Signal-To-Noise Ratio of a Single-Beam Optically Pumped Atomic Magnetometer

Yuntian Zou, Xiangyang Zhou, Jiali Liu, Wei Quan, Liwei Jiang

Published May 1, 2026• 0 citations
Publisher

Abstract

Abstract The single-beam optically pumped atomic magnetometer (OPAM) provides an effective solution for high-precision magnetic field measurements under nonzero-field conditions, including the geomagnetic field. However, the magnetometer performance is strongly influenced by the cell temperature, and the underlying mechanism by which the cell temperature affects the performance of single-beam OPAMs needs to be clarified. Based on the principle of the single-beam OPAM, a theoretical model for the scale factor is proposed, and the temperature dependence of the magnetometer signal-to-noise ratio (SNR) is investigated theoretically and experimentally. Both the theoretical analysis and experimental investigation indicate that an optimal temperature exists at which the SNR reaches its maximum, and this optimal temperature is determined for the constructed single-beam OPAM system. This work facilitates the optimization of magnetometer sensitivity and supports wearable magnetocardiography and magnetoencephalography measurements in geomagnetic field environments.

DOI
10.1088/1742-6596/3249/1/012016

Related papers

Optimal Magneto‐Optical Angle in Single‐Beam Optically Pumped Atomic Magnetometers Considering the Spatial Distribution of Spin Polarization

Yuntian Zou, Chi Fang, Jiali Liu +7 more

ABSTRACT Single‐beam optically pumped atomic magnetometers (OPAMs) are promising tools for biomagnetic measurements in nonzero‐field environments owing to their high sensitivity and compactness. However, the angle between the external bias magnetic field and the pump light affects the spin polarization of the atomic ensemble, thereby influencing the magnetometer performance and making the optimization of the magneto‐optical angle essential. In this study, a spatially resolved steady‐state spin polarization model incorporating the magneto‐optical angle is established for the first time, and an analytical expression of the spin precession signal under RF magnetic field excitation is derived. It is demonstrated that an optimal angle exists at which the magnetometer exhibits the maximum response and the highest sensitivity, which is experimentally determined to be 26° in our single‐beam OPAM. At this angle, the combined influence of the steady‐state spin polarization, spin precession projection, transmitted light intensity, and transverse spin relaxation reaches an optimal overall state, leading to a 14% enhancement in sensitivity and a 32% reduction in detection noise compared with the conventional 45° configuration. These findings provide guidance for optimizing the experimental parameters of single‐beam OPAMs for weak magnetic signal detection in nonzero‐field environments.

Advanced Quantum Technologies•Jan 1, 2026•1 citation

Ultrasensitive SERF atomic magnetometer with a miniaturized hybrid vapor cell

Yintao Ma, Yao Chen, Mingzhi Yu +8 more

Abstract The chip-scale hybrid optical pumping spin-exchange relaxation-free (SERF) atomic magnetometer with a single-beam arrangement has prominent applications in biomagnetic measurements because of its outstanding features, including ultrahigh sensitivity, an enhanced signal-to-noise ratio, homogeneous spin polarization and a much simpler optical configuration than other devices. In this work, a miniaturized single-beam hybrid optical pumping SERF atomic magnetometer based on a microfabricated atomic vapor cell is demonstrated. Although the optically thin Cs atoms are spin-polarized, the dense Rb atoms determine the experimental results. The enhanced signal strength and narrowed resonance linewidth are experimentally proven, which shows the superiority of the proposed magnetometer scheme. By using a differential detection scheme, we effectively suppress optical noise with an approximate five-fold improvement. Moreover, the cell temperature markedly affects the performance of the magnetometer. We systematically investigate the effects of temperature on the magnetometer parameters. The theoretical basis for these effects is explained in detail. The developed miniaturized magnetometer has an optimal magnetic sensitivity of 20 fT/Hz 1/2 . The presented work provides a foundation for the chip-scale integration of ultrahighly sensitive quantum magnetometers that can be used for forward-looking magnetocardiography (MCG) and magnetoencephalography (MEG) applications.

Microsystems & Nanoengineering•Aug 30, 2024•62 citations

Multi-Parameter Optimization of Rubidium Laser Optically Pumped Magnetometers with Geomagnetic Field Intensity

Kun Xu, Xiuyan Ren, Yujie Xiang +7 more

Rubidium laser optically pumped magnetometers (OPMs) are widely used magnetic sensors based on the Zeeman effect, laser pumping, and magnetic resonance principles. They measure the magnetic field by measuring the magnetic resonance signal passing through a rubidium atomic gas cell. The quality of the magnetic resonance signal is a necessary condition for a magnetometer to achieve high sensitivity. In this research, to obtain the best magnetic resonance signal of rubidium laser OPMs in the Earth’s magnetic field intensity, the experiment system of rubidium laser OPMs is built with a rubidium atomic gas cell as the core component. The linewidth and amplitude ratio (LAR) of magnetic resonance signals is utilized as the optimization objective function. The magnetic resonance signals of the magnetometer experiment system are experimentally measured for different laser frequencies, radio frequency (RF) intensities, laser powers, and atomic gas cell temperatures in a background magnetic field of 50,765 nT. The experimental results indicate that optimizing these parameters can reduce the LAR by one order of magnitude. This shows that the optimal parameter combination can effectively improve the sensitivity of the magnetometer. The sensitivity defined using the noise spectral density measured under optimal experimental parameters is 1.5 pT/Hz1/2@1 Hz. This work will provide key technical support for rubidium laser OPMs’ product development.

Sensors•Nov 2, 2023•6 citations

Assessment of Relaxation Components in Optically Pumped Magnetometers Under Operational Conditions

Huanyu Zhou, Yi Zhangu, Jin Liu +3 more

The deterioration of spin coherence has been a significant challenge in the field of quantum magnetic measurements based on optically pumped atomic magnetometers (OPAMs). However, measurement and evaluation methods for specific relaxation components of OPAMs under working conditions remain lacking, which impedes further improvement in OPAM performance. To address this, we propose a methodology for quantifying the relaxation components of an OPAM under realistic operating conditions. Using this method, we confirm the existence of an anomalous relaxation mechanism induced by radio-frequency (RF) magnetic fields and develop an empirical expression to describe its behavior. The results experimentally demonstrate that, in addition to the well-known spin-exchange relaxation, the dominant contributions to spin relaxation arise from optical pumping and RF magnetic fields. This work paves the way for sensitivity enhancement in quantum magnetometry and refines the theoretical understanding of relaxation mechanisms in OPAMs.

IEEE Transactions on Instrumentation and Measurement•Jan 1, 2026•1 citation

Portable single-beam atomic total-field magnetometer for stand-off magnetic sensing

Heonsik Lee, Hyunbeen Lee, Minseok Choi +2 more

Optically pumped atomic magnetometers (OPAMs) offer high sensitivity at room temperature and are increasingly considered for portable magnetic sensing in geomagnetic-field environments. Here, we report a handheld-scale, single-beam scalar 87Rb OPAM with a sensor-head volume of approximately 110 ml. The device operates in an all-optical Bell–Bloom configuration and uses digital lock-in, dispersive tracking of the 87Rb Larmor resonance, implemented with a hybrid electronics stack that combines in-house control hardware with commercial modules. A single frequency-modulated laser beam performs both pumping and probing without RF coils. All signal processing is realized in Python on a single-board computer paired with a commercial off-the-shelf data-acquisition module, enabling immediate deployment without dedicated signal-processing hardware. The magnetometer has an intrinsic in-band field sensitivity of approximately 21 pT/Hz, estimated from the lock-in dispersion slope, over a 0.1–30 Hz closed-loop in-band region with a digital-output rate of 200 samples/s. In an unshielded Earth-field deployment, we detect repeatable transient magnetic signatures from a controlled elevator motion sequence and quantify standoff observability over sensor-elevator distances from 1.25 m to 10 m. These results show that compact scalar OPAMs can provide bandwidth and range-resolved event sensitivity suitable for field-deployable magnetic anomaly detection and infrastructure monitoring in realistic geomagnetic environments.

arXiv:2601.08716•Journal of Applied Physics•Jun 16, 2026•0 citations

A plateau in the sensitivity of a compact optically pumped atomic magnetometer

Natsuhiko Mizutani, Kazuhisa Okano, Kazuhiro Ban +3 more

In a compact optically pumped atomic magnetometer (OPAM), there is a plateau in the sensitivity where the dependence of the sensitivity on pumping power is small compared with that predicted by the uniform polarization model. The mechanism that generates this plateau was explained by numerical analysis. The distribution of spin polarization in the alkali metal cell of an OPAM was modeled using the Bloch equation incorporating a diffusion term and an equation for the attenuation of the pump beam. The model was well-fitted to the experimental results for a module with a cubic cell with 20 mm sides and pump and probe beams with 8 mm diameter. On the plateau, strong magnetic response was generated at the regions that were not illuminated directly by the intense pump beam, while at the same time spin polarization as large as 0.5 was maintained due to diffusion of the spin-polarized atoms. Thus, the sensitivity of the magnetometer monitored with a probe beam decreases only slightly with increasing pump beam intensity because the spin polarization under an intense pump beam is saturated. This plateau, which is characteristic of this type of magnetometer using a narrow pump and probe beams, can be used in arrays of magnetometers because it enables stable operation with little sensitivity fluctuation from changes in pump beam power.

AIP Advances•May 1, 2014•12 citations
Abstract The single-beam optically pumped atomic magnetometer (OPAM) provides an effective solution for high-precision magnetic field measurements under nonzero-field conditions, including the geomagnetic field. However, the magnetometer performance is strongly influenced by the cell temperature, and the underlying mechanism by which the cell temperature affects the performance of single-beam OPAMs needs to be clarified. Based on the principle of the single-beam OPAM, a theoretical model for the scale factor is proposed, and the temperature dependence of the magnetometer signal-to-noise ratio (SNR) is investigated theoretically and experimentally. Both the theoretical analysis and experimental investigation indicate that an optimal temperature exists at which the SNR reaches its maximum, and this optimal temperature is determined for the constructed single-beam OPAM system. This work facilitates the optimization of magnetometer sensitivity and supports wearable magnetocardiography and magnetoencephalography measurements in geomagnetic field environments.
ABSTRACT Single‐beam optically pumped atomic magnetometers (OPAMs) are promising tools for biomagnetic measurements in nonzero‐field environments owing to their high sensitivity and compactness. However, the angle between the external bias magnetic field and the pump light affects the spin polarization of the atomic ensemble, thereby influencing the magnetometer performance and making the optimization of the magneto‐optical angle essential. In this study, a spatially resolved steady‐state spin polarization model incorporating the magneto‐optical angle is established for the first time, and an analytical expression of the spin precession signal under RF magnetic field excitation is derived. It is demonstrated that an optimal angle exists at which the magnetometer exhibits the maximum response and the highest sensitivity, which is experimentally determined to be 26° in our single‐beam OPAM. At this angle, the combined influence of the steady‐state spin polarization, spin precession projection, transmitted light intensity, and transverse spin relaxation reaches an optimal overall state, leading to a 14% enhancement in sensitivity and a 32% reduction in detection noise compared with the conventional 45° configuration. These findings provide guidance for optimizing the experimental parameters of single‐beam OPAMs for weak magnetic signal detection in nonzero‐field environments.
Abstract The chip-scale hybrid optical pumping spin-exchange relaxation-free (SERF) atomic magnetometer with a single-beam arrangement has prominent applications in biomagnetic measurements because of its outstanding features, including ultrahigh sensitivity, an enhanced signal-to-noise ratio, homogeneous spin polarization and a much simpler optical configuration than other devices. In this work, a miniaturized single-beam hybrid optical pumping SERF atomic magnetometer based on a microfabricated atomic vapor cell is demonstrated. Although the optically thin Cs atoms are spin-polarized, the dense Rb atoms determine the experimental results. The enhanced signal strength and narrowed resonance linewidth are experimentally proven, which shows the superiority of the proposed magnetometer scheme. By using a differential detection scheme, we effectively suppress optical noise with an approximate five-fold improvement. Moreover, the cell temperature markedly affects the performance of the magnetometer. We systematically investigate the effects of temperature on the magnetometer parameters. The theoretical basis for these effects is explained in detail. The developed miniaturized magnetometer has an optimal magnetic sensitivity of 20 fT/Hz 1/2 . The presented work provides a foundation for the chip-scale integration of ultrahighly sensitive quantum magnetometers that can be used for forward-looking magnetocardiography (MCG) and magnetoencephalography (MEG) applications.
Rubidium laser optically pumped magnetometers (OPMs) are widely used magnetic sensors based on the Zeeman effect, laser pumping, and magnetic resonance principles. They measure the magnetic field by measuring the magnetic resonance signal passing through a rubidium atomic gas cell. The quality of the magnetic resonance signal is a necessary condition for a magnetometer to achieve high sensitivity. In this research, to obtain the best magnetic resonance signal of rubidium laser OPMs in the Earth’s magnetic field intensity, the experiment system of rubidium laser OPMs is built with a rubidium atomic gas cell as the core component. The linewidth and amplitude ratio (LAR) of magnetic resonance signals is utilized as the optimization objective function. The magnetic resonance signals of the magnetometer experiment system are experimentally measured for different laser frequencies, radio frequency (RF) intensities, laser powers, and atomic gas cell temperatures in a background magnetic field of 50,765 nT. The experimental results indicate that optimizing these parameters can reduce the LAR by one order of magnitude. This shows that the optimal parameter combination can effectively improve the sensitivity of the magnetometer. The sensitivity defined using the noise spectral density measured under optimal experimental parameters is 1.5 pT/Hz1/2@1 Hz. This work will provide key technical support for rubidium laser OPMs’ product development.
The deterioration of spin coherence has been a significant challenge in the field of quantum magnetic measurements based on optically pumped atomic magnetometers (OPAMs). However, measurement and evaluation methods for specific relaxation components of OPAMs under working conditions remain lacking, which impedes further improvement in OPAM performance. To address this, we propose a methodology for quantifying the relaxation components of an OPAM under realistic operating conditions. Using this method, we confirm the existence of an anomalous relaxation mechanism induced by radio-frequency (RF) magnetic fields and develop an empirical expression to describe its behavior. The results experimentally demonstrate that, in addition to the well-known spin-exchange relaxation, the dominant contributions to spin relaxation arise from optical pumping and RF magnetic fields. This work paves the way for sensitivity enhancement in quantum magnetometry and refines the theoretical understanding of relaxation mechanisms in OPAMs.
Optically pumped atomic magnetometers (OPAMs) offer high sensitivity at room temperature and are increasingly considered for portable magnetic sensing in geomagnetic-field environments. Here, we report a handheld-scale, single-beam scalar 87Rb OPAM with a sensor-head volume of approximately 110 ml. The device operates in an all-optical Bell–Bloom configuration and uses digital lock-in, dispersive tracking of the 87Rb Larmor resonance, implemented with a hybrid electronics stack that combines in-house control hardware with commercial modules. A single frequency-modulated laser beam performs both pumping and probing without RF coils. All signal processing is realized in Python on a single-board computer paired with a commercial off-the-shelf data-acquisition module, enabling immediate deployment without dedicated signal-processing hardware. The magnetometer has an intrinsic in-band field sensitivity of approximately 21 pT/Hz, estimated from the lock-in dispersion slope, over a 0.1–30 Hz closed-loop in-band region with a digital-output rate of 200 samples/s. In an unshielded Earth-field deployment, we detect repeatable transient magnetic signatures from a controlled elevator motion sequence and quantify standoff observability over sensor-elevator distances from 1.25 m to 10 m. These results show that compact scalar OPAMs can provide bandwidth and range-resolved event sensitivity suitable for field-deployable magnetic anomaly detection and infrastructure monitoring in realistic geomagnetic environments.
In a compact optically pumped atomic magnetometer (OPAM), there is a plateau in the sensitivity where the dependence of the sensitivity on pumping power is small compared with that predicted by the uniform polarization model. The mechanism that generates this plateau was explained by numerical analysis. The distribution of spin polarization in the alkali metal cell of an OPAM was modeled using the Bloch equation incorporating a diffusion term and an equation for the attenuation of the pump beam. The model was well-fitted to the experimental results for a module with a cubic cell with 20 mm sides and pump and probe beams with 8 mm diameter. On the plateau, strong magnetic response was generated at the regions that were not illuminated directly by the intense pump beam, while at the same time spin polarization as large as 0.5 was maintained due to diffusion of the spin-polarized atoms. Thus, the sensitivity of the magnetometer monitored with a probe beam decreases only slightly with increasing pump beam intensity because the spin polarization under an intense pump beam is saturated. This plateau, which is characteristic of this type of magnetometer using a narrow pump and probe beams, can be used in arrays of magnetometers because it enables stable operation with little sensitivity fluctuation from changes in pump beam power.