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

Key engineering materials

Spin Spatial Frequency Response of Atomic Magnetometer

Ling-Xiao Yin, Jing Ling Chen

Published Nov 1, 2018• 1 citation
Publisher

Abstract

We describe a method for measuring the spin spatial frequency response in a Cs vapor cell by using a digital micro-mirror device (DMD) to modulate the pumping light both spatially and temporally. An equivalent space-alternative magnetic field is created by this way. The pumping light through the Cs vapor cell is measured and analyzed in spatial frequency domain. We obtain the spatial frequency response of the Cs vapor cell from 1.4 cm-1to 364.9 cm-1. The theoretical results of the spatial frequency response according to Fick's second diffusion law agree with the experimental results. This method provides an alternate approach for spatial characterization and three-dimensional imaging of spins.

DOI
10.4028/www.scientific.net/kem.787.81

Related papers

Observation and analysis of the spatial frequency response of an atomic magnetometer

Haifeng Dong, Ling-Xiao Yin, Ai-Xian Li +3 more

An atomic magnetometer is an ultra-high-sensitivity sensor that measures magnetic fields by means of atomic spin polarization. The spatial frequency response (SFR), which describes the spin polarizations corresponding to the field at different spatial frequencies, is an important property of atomic magnetometers. To characterize the SFR, one must generate a spatially varying field with scannable spatial frequencies (in units of mm−1), a concept that is similar to that in the time domain. However, it is much more difficult to generate a varying magnetic field spatially using traditional magnetic coils than it is to do so temporally. We generate an equivalent field Bysin⁡(ξx) with spatial frequency ξ from 0.14 mm−1 to 36.5 mm−1 by modulating the pump laser beam with a digital micromirror device and then obtain the SFR of a Cs atomic magnetometer by measuring the spin polarization of Cs at different spatial frequencies. The experimentally obtained SFR agrees well with the response calculated based on the Bloch equations and Fick’s second diffusion law. We also discuss a new definition of spatial resolution that can be used to characterize and compare the background spatial resolutions of different atomic magnetometers.

Journal of Applied Physics•Jan 11, 2019•4 citations

High spatial resolution multi-channel optically pumped atomic magnetometer based on a spatial light modulator

Xiujie Fang, Kai Wei, Tian Zhao +5 more

Ultra-sensitive multi-channel optically pumped atomic magnetometers based on the spin-exchange relaxation-free (SERF) effect are powerful tools for applications in the field of magnetic imaging. To simultaneously achieve ultra-high spatial resolution and ultra-high magnetic field sensitivity, we proposed a high-resolution multi-channel SERF atomic magnetometer for two-dimensional magnetic field measurements based on a digital micro-mirror device (DMD) as the spatial light modulator for a single vapor cell. Under the optimal experimental conditions obtained via spatial and temporal modulation of the probe light, we first demonstrated that the average sensitivity of the proposed 25-channel magnetometer was approximately 25fT/Hz 1/2 with a spatial resolution of 216µm. Then, we measured the magnetic field distribution generated by a gradient coil and compared the experimentally obtained distributions with those calculated via finite element simulation. The obtained g value of 99.2% indicated good agreement between our experimental results and the theoretical calculations, thereby confirming that our proposed multi-channel SERF magnetometer was effective at measuring magnetic field distributions with an ultra-high spatial resolution.

Optics Express•Aug 14, 2020•46 citations

A Novel Measurement Method for Spin Polarization Three Axis Spatial Distribution in Spin-Exchange Relaxation Free Atomic Magnetometer

Xiujie Fang, Jin Chun Li, Yanning Ma +5 more

The measurement of atomic spin polarization distribution in spin-exchange relaxation free (SERF) magnetometer is an important topic for improving the sensitivity and consistency of multi-channel magnetic field measurement applications. A novel spin polarization spatial distribution measurement method is presented based on the transient response of the magnetometer after modulating the pumped light with a chopper. Polarization is obtained by a slow-down factor based on the fast spin-exchange interaction effects. Longitudinal and transverse polarization distributions are measured simultaneously without interrupting the operation of the SERF status. Under different oscillating magnetic fields, the spin polarization is measured at the cell centroid. Residual magnetic field inside the magnetometer is obtained from the linear relationship between the precession frequency and the oscillating magnetic field. The one-dimensional polarization distributions in the x, y, and z axes are measured using a digital micromirror device with a resolution of 0.25 cm. The measurement results conform to the Lambert-Bier absorption law and the Gaussian distribution law. Furthermore, 7 × 7 two-dimensional spatial distribution measurements of polarization on the xy and yz planes are performed. Nonuniformity of 1.04 in the xy plane and 1.82 in the yz plane in the built magnetometer. Compared with other measurement methods, the distribution measurement method proposed is independent of optical depth and suitable for low polarization and high polarization applications. Based on the results of the proposed measurement method of spin polarization spatial distribution, further compensation can improve the application consistency of multi-channel magnetic field measurements and improve the sensitivity of single-channel differential measurements.

Photonics•Mar 20, 2023•2 citations

Spin image of an atomic vapor cell with a resolution smaller than the diffusion crosstalk free distance

Hai-Feng Dong, Jing-Ling Chen, Ji-Min Li +4 more

The diffusion crosstalk free distance is an important parameter for spin images in atomic vapor cells and is also regarded as a limit on the spatial resolution. However, by modulating the pumping light both spatially and temporally using a digital micromirror device, a spin image of a vapor cell has been obtained with a distinguishable stripe width of 13.7 μm, which is much smaller than the corresponding diffusion crosstalk free distance of ∼138 μm. The fundamental limit on the spatial resolution as determined by diffusion and the uncertainty principle is analyzed.

arXiv:1904.08552•Journal of Applied Physics•Jun 27, 2019•14 citations

2D Microscopy of Magnetic Field Using Atomic Vapor Cell

Haifeng Dong, Chen Liu, Jun-Jun Sang

2D microscopy of magnetic field with high spatial resolution is realized using atomic vapor cell and digital micro mirror device. Cesium atom spins are polarized and measured using an elliptically polarized light simultaneously. The Allen variance of the field measurement is characterized to be from 18pT @ 109μm to 8pT @ 438μm.

IEEE International Conference on Nano/Micro Engineered and Molecular Systems•Apr 25, 2021•0 citations

A method of modulating spin-polarized states with high spatiotemporal resolution in alkali-metal atomic vapor cell

Donghui Ma, HE Xinxin, HUA Zeyu +7 more

With the state-of-the-art quantum measurement devices, such as atomic clocks, atomic gyroscopes, and atomic magnetometers, as their central components, the spatiotemporal evolution of atomic spin polarization in the atomic vapor cell has a major effect on both increasing the bandwidth of magnetometer and improving the accuracy of magnetic gradient measurements. However, the major factor impeding the further improvement of the performance of quantum measurement instrument is the inherent static nature of the traditional intra-vapor cell segmentation imaging technique, which makes it challenging to achieve the real-time capture of the dynamic evolution of atomic spin states. In this work, we suggest a dynamic spin imaging method for alkali metal atomic vapor cells with real-time modification of atomic spin polarization states in order to overcome this technological difficulty. In particular, to ensure that the laser can precisely act on the alkali metal atoms in various regions in the vapor cell, we employ a complex beam array management system to modify the on/off state of the laser beams at various positions in the spatial dimension in real time. In the meantime, we generate laser fields with particular spatial distribution and frequency characteristics by using frequency modulation techniques in the time series to accurately regulate the on-off frequency of each laser beam in the beam array. These laser beams cause dynamic changes in the atomic spin polarization state by interacting with alkali metal atoms at various points in the vapor cell. Through precise adjustment of the laser properties, we can see and study the dynamic evolution of the atomic spin-polarization state in real time. According to the experimental data, the technology outperforms the traditional static spin imaging techniques by achieving an excellent temporal resolution of 355 frames per second and a spatial resolution of 95.9 micrometers. The effective use of this method enables us to monitor and evaluate the dynamic aspects of magnetic field distribution with unprecedented precision, also greatly enhance our understanding of the dynamic characteristics of atomic spin polarization.

Acta Physica Sinica•Jan 1, 2025•2 citations
We describe a method for measuring the spin spatial frequency response in a Cs vapor cell by using a digital micro-mirror device (DMD) to modulate the pumping light both spatially and temporally. An equivalent space-alternative magnetic field is created by this way. The pumping light through the Cs vapor cell is measured and analyzed in spatial frequency domain. We obtain the spatial frequency response of the Cs vapor cell from 1.4 cm-1to 364.9 cm-1. The theoretical results of the spatial frequency response according to Fick's second diffusion law agree with the experimental results. This method provides an alternate approach for spatial characterization and three-dimensional imaging of spins.
An atomic magnetometer is an ultra-high-sensitivity sensor that measures magnetic fields by means of atomic spin polarization. The spatial frequency response (SFR), which describes the spin polarizations corresponding to the field at different spatial frequencies, is an important property of atomic magnetometers. To characterize the SFR, one must generate a spatially varying field with scannable spatial frequencies (in units of mm−1), a concept that is similar to that in the time domain. However, it is much more difficult to generate a varying magnetic field spatially using traditional magnetic coils than it is to do so temporally. We generate an equivalent field Bysin⁡(ξx) with spatial frequency ξ from 0.14 mm−1 to 36.5 mm−1 by modulating the pump laser beam with a digital micromirror device and then obtain the SFR of a Cs atomic magnetometer by measuring the spin polarization of Cs at different spatial frequencies. The experimentally obtained SFR agrees well with the response calculated based on the Bloch equations and Fick’s second diffusion law. We also discuss a new definition of spatial resolution that can be used to characterize and compare the background spatial resolutions of different atomic magnetometers.
Ultra-sensitive multi-channel optically pumped atomic magnetometers based on the spin-exchange relaxation-free (SERF) effect are powerful tools for applications in the field of magnetic imaging. To simultaneously achieve ultra-high spatial resolution and ultra-high magnetic field sensitivity, we proposed a high-resolution multi-channel SERF atomic magnetometer for two-dimensional magnetic field measurements based on a digital micro-mirror device (DMD) as the spatial light modulator for a single vapor cell. Under the optimal experimental conditions obtained via spatial and temporal modulation of the probe light, we first demonstrated that the average sensitivity of the proposed 25-channel magnetometer was approximately 25fT/Hz 1/2 with a spatial resolution of 216µm. Then, we measured the magnetic field distribution generated by a gradient coil and compared the experimentally obtained distributions with those calculated via finite element simulation. The obtained g value of 99.2% indicated good agreement between our experimental results and the theoretical calculations, thereby confirming that our proposed multi-channel SERF magnetometer was effective at measuring magnetic field distributions with an ultra-high spatial resolution.
The measurement of atomic spin polarization distribution in spin-exchange relaxation free (SERF) magnetometer is an important topic for improving the sensitivity and consistency of multi-channel magnetic field measurement applications. A novel spin polarization spatial distribution measurement method is presented based on the transient response of the magnetometer after modulating the pumped light with a chopper. Polarization is obtained by a slow-down factor based on the fast spin-exchange interaction effects. Longitudinal and transverse polarization distributions are measured simultaneously without interrupting the operation of the SERF status. Under different oscillating magnetic fields, the spin polarization is measured at the cell centroid. Residual magnetic field inside the magnetometer is obtained from the linear relationship between the precession frequency and the oscillating magnetic field. The one-dimensional polarization distributions in the x, y, and z axes are measured using a digital micromirror device with a resolution of 0.25 cm. The measurement results conform to the Lambert-Bier absorption law and the Gaussian distribution law. Furthermore, 7 × 7 two-dimensional spatial distribution measurements of polarization on the xy and yz planes are performed. Nonuniformity of 1.04 in the xy plane and 1.82 in the yz plane in the built magnetometer. Compared with other measurement methods, the distribution measurement method proposed is independent of optical depth and suitable for low polarization and high polarization applications. Based on the results of the proposed measurement method of spin polarization spatial distribution, further compensation can improve the application consistency of multi-channel magnetic field measurements and improve the sensitivity of single-channel differential measurements.
The diffusion crosstalk free distance is an important parameter for spin images in atomic vapor cells and is also regarded as a limit on the spatial resolution. However, by modulating the pumping light both spatially and temporally using a digital micromirror device, a spin image of a vapor cell has been obtained with a distinguishable stripe width of 13.7 μm, which is much smaller than the corresponding diffusion crosstalk free distance of ∼138 μm. The fundamental limit on the spatial resolution as determined by diffusion and the uncertainty principle is analyzed.
With the state-of-the-art quantum measurement devices, such as atomic clocks, atomic gyroscopes, and atomic magnetometers, as their central components, the spatiotemporal evolution of atomic spin polarization in the atomic vapor cell has a major effect on both increasing the bandwidth of magnetometer and improving the accuracy of magnetic gradient measurements. However, the major factor impeding the further improvement of the performance of quantum measurement instrument is the inherent static nature of the traditional intra-vapor cell segmentation imaging technique, which makes it challenging to achieve the real-time capture of the dynamic evolution of atomic spin states. In this work, we suggest a dynamic spin imaging method for alkali metal atomic vapor cells with real-time modification of atomic spin polarization states in order to overcome this technological difficulty. In particular, to ensure that the laser can precisely act on the alkali metal atoms in various regions in the vapor cell, we employ a complex beam array management system to modify the on/off state of the laser beams at various positions in the spatial dimension in real time. In the meantime, we generate laser fields with particular spatial distribution and frequency characteristics by using frequency modulation techniques in the time series to accurately regulate the on-off frequency of each laser beam in the beam array. These laser beams cause dynamic changes in the atomic spin polarization state by interacting with alkali metal atoms at various points in the vapor cell. Through precise adjustment of the laser properties, we can see and study the dynamic evolution of the atomic spin-polarization state in real time. According to the experimental data, the technology outperforms the traditional static spin imaging techniques by achieving an excellent temporal resolution of 355 frames per second and a spatial resolution of 95.9 micrometers. The effective use of this method enables us to monitor and evaluate the dynamic aspects of magnetic field distribution with unprecedented precision, also greatly enhance our understanding of the dynamic characteristics of atomic spin polarization.