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 Express

Optimisation of a radio-frequency atomic magnetometer: a Uniform Design approach

Han Yao, Benjamin Maddox, Yuval Cohen, Ferruccio Renzoni

Published Dec 27, 2021• 9 citations
Publisher

Abstract

High-sensitivity operation of a radio-frequency atomic magnetometer (RF-AM) requires careful setting of the system parameters, including the lasers intensity and detuning, and the vapour cell temperature. The identification of the optimal operating parameters, which ensures high sensitivity, is typically performed empirically and is often a lengthy process, which is especially labour intensive if frequent retuning of the magnetometer is required to perform different tasks. This paper demonstrates an efficient approach to RF-AM performance optimisation which relies on an open-loop optimisation technique based on Uniform Design (UD). This paper specifically describes the optimisation of an unshielded RF-AM based on a 4-factor-12-level UD of the experimental parameters space. The proposed procedure is shown to lead to the efficient optimisation of the atomic magnetometer at different frequencies, and is applicable to both AC and DC sensitivity optimisation. The procedure does not require any detailed knowledge of the model underlying the operation of the RF-AM and is effective in reducing the number of experimental runs required for the optimisation. It is ideally suited to self-calibration of devices without human supervision.

DOI
10.1364/oe.448470

Related papers

Neural network-aided optimisation of a radio-frequency atomic magnetometer

Han Yao, Benjamin Maddox, Ferruccio Renzoni

Efficient unsupervised optimisation of atomic magnetometers is a requirement in many applications, where direct intervention of an operator is not feasible. The efficient extraction of the optimal operating conditions from a small sample of experimental data requires a robust automated regression of the available data. Here we address this issue and propose the use of general regression neural networks as a tool for the optimisation of atomic magnetometers which does not require human supervision and is efficient, as it is ideally suited to operating with a small sample of data as input. As a case study, we specifically demonstrate the optimisation of an unshielded radio-frequency atomic magnetometer by using a general regression neural network which establishes a mapping between three input variables, the cell temperature, the pump beam power and the probe beam power, and one output variable, the AC sensitivity. The optimisation results into an AC sensitivity of 44 fT/Hz at 26 kHz.

Optics Express•Jul 19, 2023•6 citations

High-Sensitivity Operation of Unshielded Radio Frequency Atomic Magnetometers Using Phase-Lock Techniques

Han Yao, Ferruccio Renzoni

High sensitivity operation of radio-frequency atomic magnetometers in unshielded environment requires compensation of low-frequency fluctuations of the ambient magnetic field. Here we demonstrate the use of phase-lock techniques to stabilise the magnetic environment and achieve high sensitivity at high frequencies. This is achieved by using the output of the atomic magnetometer both for stabilisation and for measurement purposes. The approach is validated by a proof-of-concept in unshielded environment. The phase-lock approach is also compared to the standard approach where the magnetic environment is stabilised with the help of a set of fluxgate magnetometers, and it is shown that the phase-lock approach features superior performances in signal detection.

IEEE Transactions on Instrumentation and Measurement•Jan 1, 2025•3 citations

Ultra-sensitive high-density Rb-87 radio-frequency magnetometer

Igor Savukov, Todor S. Karaulanov, M. G. Boshier

Radio-frequency (RF) atomic magnetometers (AMs) can be used in many applications, such as magnetic resonance imaging and nuclear quadrupole resonance. High-density AMs provide both superior sensitivity and large bandwidth. Previously, high-density potassium AMs were demonstrated, but these magnetometers have various disadvantages, such as high-temperature of operation and bulky design. We demonstrate a rubidium-87 RF AM with 5 fT/Hz1/2 sensitivity (3 fT Hz1/2 probe noise), which is comparable to that of the best potassium magnetometers. Our magnetometer also features a simple fiber-optic design, providing maximum flexibility for magnetic-field measurements.

Applied Physics Letters•Jan 13, 2014•34 citations

High-sensitivity operation of an unshielded single cell radio-frequency atomic magnetometer

Han Yao, Benjamin Maddox, Ferruccio Renzoni

Real-world applications of atomic magnetometers require the ability to operate them with high-sensitivity in the presence of magnetic noise. In the present work, high-sensitivity operation of unshielded atomic magnetometers in a magnetically noisy environment is demonstrated. The distinguishing feature of the demonstrated approach is the implementation of active in-situ bias field stabilization using multiple fluxgate magnetometers. This is combined with the use of a counter-propagating pump and triple-pass probe configuration, to maximize the atomic polarization and the probe rotation respectively, so to reach high-sensitivity. The improvement in sensitivity of the unshielded system with respect to previous realizations is fully characterized, with the contributions of the different modifications of the apparatus individually quantified. The presented set-up is suitable for the detection of long-range magnetic fields, where shielding or differential measurements using multi-sensor set-ups do not constitute viable options.

Optics Express•Oct 21, 2022•29 citations

A Performance-Enhanced Closed-Loop SERF Atomic Magnetometer

Ziao Liu, Jianli Li, Xiaoyu Li +3 more

The spin-exchange relaxation-free (SERF) atomic magnetometers (AMs) exhibit ultrahigh sensitivity in ultraweak magnetic field measurement, but their narrow bandwidth constrains the scope of their applications. To increase the bandwidth, magnetic field closed-loop control technology has been introduced into AMs with demonstrated efficacy. However, previous research on closed-loop AMs resulted in signal distortion problems, primarily due to imprecise closed-loop models and control parameters selection without theoretical support. This problem is specifically characterized by the unexpected amplification or reduction of signals at certain frequencies, directly leading to the degradation of the frequency performance of the closed-loop AM, making it unsuitable for applications requiring full-bandwidth measurement. In this study, we proposed a performance-enhanced closed-loop SERF AM, maximizing the bandwidth while ensuring consistent performance across the entire bandwidth. An accurate closed-loop system model was first established. Subsequently, an optimal relationship between the control parameters was proposed according to the eigenvalues of the closed-loop system, and the particle swarm optimization (PSO) algorithm was introduced to determine the optimal control parameters. The improved closed-loop system was constructed in a triaxial SERF AM, achieving an average bandwidth of 410 Hz and a sensitivity of 10 fT/Hz$^{{1}/{2}}$in three axes, while ensuring consistent performance across the entire bandwidth. With the proposed method, the optimized control parameters can be obtained only by requiring the frequency response of the open-loop AM, which is convenient and useful for closed-loop AM applications.

IEEE Sensors Journal•Oct 1, 2024•5 citations

Effects of Multiple Factors on the Performance of Portable Self-Oscillating Laser Pumped Atomic Magnetometer

Kai Jin, Xu‐xing Geng, Jianfeng Xiao +7 more

Self-oscillating magnetometers with high sensitivity are widely used in fields such as biomedicine and remote sensing. However, few studies comprehensively consider the effect of different parameters on their performance. We examined the effects of laser intensity, resonance detuning, radio frequency (RF) magnetic field, and atomic cell on the performance of portable self-oscillating magnetometers. To obtain the atomic absorption spectrum, we solved the system’s master equation in the multipole moment form. In theory, we analyse the influencing factors on the atomic magnetic resonance (AMR) signal. In the experiment, we artificially varied the relevant parameters to control the trends of changes in the atomic absorption spectra and evaluated their performance. The results are beneficial for optimizing the parameters of portable self-oscillating magnetometers with a laser pump-probe structure.

IEEE Sensors Journal•Feb 19, 2024•1 citation
High-sensitivity operation of a radio-frequency atomic magnetometer (RF-AM) requires careful setting of the system parameters, including the lasers intensity and detuning, and the vapour cell temperature. The identification of the optimal operating parameters, which ensures high sensitivity, is typically performed empirically and is often a lengthy process, which is especially labour intensive if frequent retuning of the magnetometer is required to perform different tasks. This paper demonstrates an efficient approach to RF-AM performance optimisation which relies on an open-loop optimisation technique based on Uniform Design (UD). This paper specifically describes the optimisation of an unshielded RF-AM based on a 4-factor-12-level UD of the experimental parameters space. The proposed procedure is shown to lead to the efficient optimisation of the atomic magnetometer at different frequencies, and is applicable to both AC and DC sensitivity optimisation. The procedure does not require any detailed knowledge of the model underlying the operation of the RF-AM and is effective in reducing the number of experimental runs required for the optimisation. It is ideally suited to self-calibration of devices without human supervision.
Efficient unsupervised optimisation of atomic magnetometers is a requirement in many applications, where direct intervention of an operator is not feasible. The efficient extraction of the optimal operating conditions from a small sample of experimental data requires a robust automated regression of the available data. Here we address this issue and propose the use of general regression neural networks as a tool for the optimisation of atomic magnetometers which does not require human supervision and is efficient, as it is ideally suited to operating with a small sample of data as input. As a case study, we specifically demonstrate the optimisation of an unshielded radio-frequency atomic magnetometer by using a general regression neural network which establishes a mapping between three input variables, the cell temperature, the pump beam power and the probe beam power, and one output variable, the AC sensitivity. The optimisation results into an AC sensitivity of 44 fT/Hz at 26 kHz.
High sensitivity operation of radio-frequency atomic magnetometers in unshielded environment requires compensation of low-frequency fluctuations of the ambient magnetic field. Here we demonstrate the use of phase-lock techniques to stabilise the magnetic environment and achieve high sensitivity at high frequencies. This is achieved by using the output of the atomic magnetometer both for stabilisation and for measurement purposes. The approach is validated by a proof-of-concept in unshielded environment. The phase-lock approach is also compared to the standard approach where the magnetic environment is stabilised with the help of a set of fluxgate magnetometers, and it is shown that the phase-lock approach features superior performances in signal detection.
Radio-frequency (RF) atomic magnetometers (AMs) can be used in many applications, such as magnetic resonance imaging and nuclear quadrupole resonance. High-density AMs provide both superior sensitivity and large bandwidth. Previously, high-density potassium AMs were demonstrated, but these magnetometers have various disadvantages, such as high-temperature of operation and bulky design. We demonstrate a rubidium-87 RF AM with 5 fT/Hz1/2 sensitivity (3 fT Hz1/2 probe noise), which is comparable to that of the best potassium magnetometers. Our magnetometer also features a simple fiber-optic design, providing maximum flexibility for magnetic-field measurements.
Real-world applications of atomic magnetometers require the ability to operate them with high-sensitivity in the presence of magnetic noise. In the present work, high-sensitivity operation of unshielded atomic magnetometers in a magnetically noisy environment is demonstrated. The distinguishing feature of the demonstrated approach is the implementation of active in-situ bias field stabilization using multiple fluxgate magnetometers. This is combined with the use of a counter-propagating pump and triple-pass probe configuration, to maximize the atomic polarization and the probe rotation respectively, so to reach high-sensitivity. The improvement in sensitivity of the unshielded system with respect to previous realizations is fully characterized, with the contributions of the different modifications of the apparatus individually quantified. The presented set-up is suitable for the detection of long-range magnetic fields, where shielding or differential measurements using multi-sensor set-ups do not constitute viable options.
The spin-exchange relaxation-free (SERF) atomic magnetometers (AMs) exhibit ultrahigh sensitivity in ultraweak magnetic field measurement, but their narrow bandwidth constrains the scope of their applications. To increase the bandwidth, magnetic field closed-loop control technology has been introduced into AMs with demonstrated efficacy. However, previous research on closed-loop AMs resulted in signal distortion problems, primarily due to imprecise closed-loop models and control parameters selection without theoretical support. This problem is specifically characterized by the unexpected amplification or reduction of signals at certain frequencies, directly leading to the degradation of the frequency performance of the closed-loop AM, making it unsuitable for applications requiring full-bandwidth measurement. In this study, we proposed a performance-enhanced closed-loop SERF AM, maximizing the bandwidth while ensuring consistent performance across the entire bandwidth. An accurate closed-loop system model was first established. Subsequently, an optimal relationship between the control parameters was proposed according to the eigenvalues of the closed-loop system, and the particle swarm optimization (PSO) algorithm was introduced to determine the optimal control parameters. The improved closed-loop system was constructed in a triaxial SERF AM, achieving an average bandwidth of 410 Hz and a sensitivity of 10 fT/Hz1/2^{{1}/{2}}1/2in three axes, while ensuring consistent performance across the entire bandwidth. With the proposed method, the optimized control parameters can be obtained only by requiring the frequency response of the open-loop AM, which is convenient and useful for closed-loop AM applications.
Self-oscillating magnetometers with high sensitivity are widely used in fields such as biomedicine and remote sensing. However, few studies comprehensively consider the effect of different parameters on their performance. We examined the effects of laser intensity, resonance detuning, radio frequency (RF) magnetic field, and atomic cell on the performance of portable self-oscillating magnetometers. To obtain the atomic absorption spectrum, we solved the system’s master equation in the multipole moment form. In theory, we analyse the influencing factors on the atomic magnetic resonance (AMR) signal. In the experiment, we artificially varied the relevant parameters to control the trends of changes in the atomic absorption spectra and evaluated their performance. The results are beneficial for optimizing the parameters of portable self-oscillating magnetometers with a laser pump-probe structure.