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 Optoelectronics·laser

Study of resonance curve width in Cs vapor magnetometer

Sun Weimin

Published Jan 1, 2010• 0 citations
OpenAlex

Abstract

A new magnetometer with Cs vapor in the spin exchange relaxation free(SERF) regime is described.Cs has a higher saturated vapor pressure than other alkali metals;so cesium SERF magnetometer is particularly attractive in applications that require lower power dissipation.Four factors affect atomic transverse relaxations in the SERF magnetometer,including collisions and diffusions among Cs,N2 and He,laser pumping and detecting processes;the buffer gas pressure of He that affects the relaxation is calculated and discussed emphatically in theory at 105 ℃,the result shows that the optimum buffer gas pressure is 350×133.3 Pa.Under the optimum pressure,the polarized spectrum linewidth as the function of the cell temperature is discussed briefly.It is found the least linewidth is only 3.7 Hz corresponding to the electric spin relaxation rate of 278 s-1 at 105 ℃.The result provides a help to increase the sensitivity of the magnetometer with Cs vapor.

Related papers

Study of optimum pumping intensity at Cs vapor magnetometer

Junhai Zhang, Feng Wang, Jiuxing Li +1 more

The paper describes a new magnetometer with Cs vapor in the spin exchange relaxation free (SERF) regime. Because cesium atom has a higher saturated vapor pressure than other alkali metallic atoms, so the magnetometer has required lower operated temperature. We have discussed the effect of different pumping intensities on the polarization and the pumping rate at 105°C in theory; and the result shows out the magnetometer will have maximum sensitivity when the pumping intensity is 52mW/cm2. Taking into account all relaxations including collision relaxations, diffusion relaxation and pumping relaxation from pump light, we find the relaxation rate will be about 6Hz for the cesium magnetometer with SERF.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 13, 2010•1 citation

Spin-exchange-relaxation-free magnetometry with Cs vapor

M. P. Ledbetter, Igor Savukov, Víctor M. Acosta +2 more

We describe a Cs atomic magnetometer operating in the spin-exchange-relaxation-free (SERF) regime. With a vapor cell temperature of $103\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ we achieve intrinsic magnetic resonance widths $\ensuremath{\Delta}B=17\text{ }\ensuremath{\mu}\text{G}$ corresponding to an electron spin-relaxation rate of $300\text{ }{\text{s}}^{\ensuremath{-}1}$ when the spin-exchange rate is ${\ensuremath{\Gamma}}_{\text{SE}}=14\text{ }000\text{ }{\text{s}}^{\ensuremath{-}1}$. We also observe an interesting narrowing effect due to diffusion. Signal-to-noise measurements yield a sensitivity of about $400\text{ }\text{pG}/\sqrt{\text{Hz}}$. Based on photon shot noise, we project a sensitivity of $40\text{ }\text{pG}/\sqrt{\text{Hz}}$. A theoretical optimization of the magnetometer indicates sensitivities on the order of $2\text{ }\text{pG}/\sqrt{\text{Hz}}$ should be achievable in a $1\text{ }{\text{cm}}^{3}$ volume. Because Cs has a higher saturated vapor pressure than other alkali metals, SERF magnetometers using Cs atoms are particularly attractive in applications requiring lower temperatures.

arXiv:0708.1012•Physical Review A•Mar 13, 2008•400 citations

Influence of Buffer-Gas Pressure Inside Micro Alkali Vapor Cells on the Performance of Chip-Scale SERF Magnetometers

Lei Wu, Jintang Shang, Yu Ji +2 more

Spin-exchange-relaxation-free (SERF) optical atomic magnetometers are facing the challenges of dramatic decrease of sensitivity when the alkali vapor cells become small. This paper focuses on the sensitivity improvement of the chip-scale atomic magnetometer (CSAM) by changing buffer-gas pressures inside the microfabricated vapor cells. The rubidium vapor cells with three different buffer-gas pressures were tested in the SERF magnetometer. The influences of vapor cell temperature and pumping laser power on the device sensitivity are also characterized for further optimization. Results show that the three atomic vapor cells, with N2buffer-gas pressure of 0.20, 0.88, and 2.35 amg, have sensitivities of 900, 500, and 150 fT/Hz1/2, respectively. Results indicated that when the alkali vapor cells continue to be smaller, high buffer-gas pressure would provide an effective way to reduce the wall collision and improve the performance of CSAMs.

IEEE Transactions on Components Packaging and Manufacturing Technology•Dec 21, 2017•18 citations

Influence of He Buffer Gas Pressure on Cs Atomic Polarizability

Qiang Liu, Yu Dan Sun, Yan Nan Zhuo +2 more

All optical cesium (Cs) atomic magnetometer with high sensitivity is an important technique to detect weak magnetic field. The Cs vapor cell is filled with He buffer gas to reduce spin relaxation rate. However the pressure of He also influences the Cs atomic polarizability due to pressure broadening effect. In this work, the principle of all optical Cs atomic magnetometer is analyzed. The rate equation is used to calculate Cs atomic polarizability as the pressure of He is about 100Torr and pure Cs vapor cell. The calculation shows that higher pressure of He buffer gas can decrease Cs atomic polarizability without considering spin-exchange collisions, as the pump beam frequency is locked to Cs D1 transition F=3F=4.

Applied Mechanics and Materials•Dec 1, 2013•2 citations

The Characterization of Atomic Vapor Cells for High-Sensitivity Magnetic Field Measurements in SERF Regime

Murat Salim Karabinaoğlu, Berfin Muhlise Caklı, Mehmet Hüseyin Sevim

Nowadays, quantum sensor research is a very interesting and popular topic. High-sensitivity magnetic field measurements using quantum sensors have evolved into the most sensitive magnetic field sensor category today with the invention of atomic magnetometers operating in the spin-exchange relaxation-free (SERF) regime. This letter was prepared to investigate the magnetic field sensitivity changes depending on the buffer gas, temperature, and laser intensity using indigenously produced atomic vapor cells. In addition, the aim was to determine the optimum operating conditions of the atomic magnetometer operating in the SERF regime. As a result, the resonance linewidth and signal-to-noise ratio were measured, and the minimum detectable magnetic field was calculated. According to the obtained results, the lowest magnetic field for Cells I–III was measured as 5.12, 4.21, and 4.81 pT, respectively. The lowest magnetic field of all conditions was obtained in vapor cell (Cell-II) at 100 °C with 5 mW laser intensity. As a result, it has been experimentally proven that under the same conditions, increasing the buffer gas pressure in vapor cells can narrow the resonance linewidth, and the magnetic field sensitivity can be improved by increasing the laser intensity applied to the vapor cells.

IEEE Sensors Letters•Feb 24, 2025•5 citations

Buffer Gas Pressure Optimization for Atomic Spin Relaxation Suppression in Ultra-High-Sensitivity SERF Magnetometers

Siran Li, X.-G. Lu, Yinghui Zhang +3 more

Optically pumped magnetometers (OPM) are core quantum payloads for geomagnetic remote sensing. Among them, the spin-exchange relaxation-free (SERF) OPM with aT-level ultimate sensitivity stands as mainstream. While enlarging the alkali-metal vapor cell of the SERF OPM enhances sensitivity, it triggers complex atomic spin relaxation, notably intensified magnetic field gradient relaxation. To address the dilemma of atomic spin relaxation regulation and the engineering requirements of ultra-high-sensitivity SERF magnetometers, this paper constructs an analytical model of the total relaxation rate that comprehensively considers wall-collision relaxation, spin-destruction collision relaxation, and longitudinal/transverse magnetic field gradient relaxation, etc. The analytical relationship between buffer gas pressure and total relaxation rate for a commonly used spherical vapor cell is derived, revealing the intrinsic correlation among cell size, atomic spin relaxation, and optimal pressure. Based on the theoretical model, the filling parameters of the vapor cell are optimized, and experimental measurements are carried out. The theoretical relaxation results are highly consistent with the experimental ones, realizing the precise optimization of buffer gas pressure. The optimization method proposed in this paper provides a theoretical basis and parameter guidance for the engineering preparation of alkali-metal vapor cells for high-sensitivity SERF magnetometers in remote sensing applications.

Photonics•Jun 1, 2026•0 citations
A new magnetometer with Cs vapor in the spin exchange relaxation free(SERF) regime is described.Cs has a higher saturated vapor pressure than other alkali metals;so cesium SERF magnetometer is particularly attractive in applications that require lower power dissipation.Four factors affect atomic transverse relaxations in the SERF magnetometer,including collisions and diffusions among Cs,N2 and He,laser pumping and detecting processes;the buffer gas pressure of He that affects the relaxation is calculated and discussed emphatically in theory at 105 ℃,the result shows that the optimum buffer gas pressure is 350×133.3 Pa.Under the optimum pressure,the polarized spectrum linewidth as the function of the cell temperature is discussed briefly.It is found the least linewidth is only 3.7 Hz corresponding to the electric spin relaxation rate of 278 s-1 at 105 ℃.The result provides a help to increase the sensitivity of the magnetometer with Cs vapor.
The paper describes a new magnetometer with Cs vapor in the spin exchange relaxation free (SERF) regime. Because cesium atom has a higher saturated vapor pressure than other alkali metallic atoms, so the magnetometer has required lower operated temperature. We have discussed the effect of different pumping intensities on the polarization and the pumping rate at 105°C in theory; and the result shows out the magnetometer will have maximum sensitivity when the pumping intensity is 52mW/cm2. Taking into account all relaxations including collision relaxations, diffusion relaxation and pumping relaxation from pump light, we find the relaxation rate will be about 6Hz for the cesium magnetometer with SERF.
We describe a Cs atomic magnetometer operating in the spin-exchange-relaxation-free (SERF) regime. With a vapor cell temperature of $103\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ we achieve intrinsic magnetic resonance widths $\ensuremath{\Delta}B=17\text{ }\ensuremath{\mu}\text{G}$ corresponding to an electron spin-relaxation rate of $300\text{ }{\text{s}}^{\ensuremath{-}1}$ when the spin-exchange rate is ${\ensuremath{\Gamma}}_{\text{SE}}=14\text{ }000\text{ }{\text{s}}^{\ensuremath{-}1}$. We also observe an interesting narrowing effect due to diffusion. Signal-to-noise measurements yield a sensitivity of about 400 pG/Hz400\text{ }\text{pG}/\sqrt{\text{Hz}}400 pG/Hz​. Based on photon shot noise, we project a sensitivity of 40 pG/Hz40\text{ }\text{pG}/\sqrt{\text{Hz}}40 pG/Hz​. A theoretical optimization of the magnetometer indicates sensitivities on the order of 2 pG/Hz2\text{ }\text{pG}/\sqrt{\text{Hz}}2 pG/Hz​ should be achievable in a 1 cm31\text{ }{\text{cm}}^{3}1 cm3 volume. Because Cs has a higher saturated vapor pressure than other alkali metals, SERF magnetometers using Cs atoms are particularly attractive in applications requiring lower temperatures.
Spin-exchange-relaxation-free (SERF) optical atomic magnetometers are facing the challenges of dramatic decrease of sensitivity when the alkali vapor cells become small. This paper focuses on the sensitivity improvement of the chip-scale atomic magnetometer (CSAM) by changing buffer-gas pressures inside the microfabricated vapor cells. The rubidium vapor cells with three different buffer-gas pressures were tested in the SERF magnetometer. The influences of vapor cell temperature and pumping laser power on the device sensitivity are also characterized for further optimization. Results show that the three atomic vapor cells, with N2buffer-gas pressure of 0.20, 0.88, and 2.35 amg, have sensitivities of 900, 500, and 150 fT/Hz1/2, respectively. Results indicated that when the alkali vapor cells continue to be smaller, high buffer-gas pressure would provide an effective way to reduce the wall collision and improve the performance of CSAMs.
All optical cesium (Cs) atomic magnetometer with high sensitivity is an important technique to detect weak magnetic field. The Cs vapor cell is filled with He buffer gas to reduce spin relaxation rate. However the pressure of He also influences the Cs atomic polarizability due to pressure broadening effect. In this work, the principle of all optical Cs atomic magnetometer is analyzed. The rate equation is used to calculate Cs atomic polarizability as the pressure of He is about 100Torr and pure Cs vapor cell. The calculation shows that higher pressure of He buffer gas can decrease Cs atomic polarizability without considering spin-exchange collisions, as the pump beam frequency is locked to Cs D1 transition F=3F=4.
Nowadays, quantum sensor research is a very interesting and popular topic. High-sensitivity magnetic field measurements using quantum sensors have evolved into the most sensitive magnetic field sensor category today with the invention of atomic magnetometers operating in the spin-exchange relaxation-free (SERF) regime. This letter was prepared to investigate the magnetic field sensitivity changes depending on the buffer gas, temperature, and laser intensity using indigenously produced atomic vapor cells. In addition, the aim was to determine the optimum operating conditions of the atomic magnetometer operating in the SERF regime. As a result, the resonance linewidth and signal-to-noise ratio were measured, and the minimum detectable magnetic field was calculated. According to the obtained results, the lowest magnetic field for Cells I–III was measured as 5.12, 4.21, and 4.81 pT, respectively. The lowest magnetic field of all conditions was obtained in vapor cell (Cell-II) at 100 °C with 5 mW laser intensity. As a result, it has been experimentally proven that under the same conditions, increasing the buffer gas pressure in vapor cells can narrow the resonance linewidth, and the magnetic field sensitivity can be improved by increasing the laser intensity applied to the vapor cells.
Optically pumped magnetometers (OPM) are core quantum payloads for geomagnetic remote sensing. Among them, the spin-exchange relaxation-free (SERF) OPM with aT-level ultimate sensitivity stands as mainstream. While enlarging the alkali-metal vapor cell of the SERF OPM enhances sensitivity, it triggers complex atomic spin relaxation, notably intensified magnetic field gradient relaxation. To address the dilemma of atomic spin relaxation regulation and the engineering requirements of ultra-high-sensitivity SERF magnetometers, this paper constructs an analytical model of the total relaxation rate that comprehensively considers wall-collision relaxation, spin-destruction collision relaxation, and longitudinal/transverse magnetic field gradient relaxation, etc. The analytical relationship between buffer gas pressure and total relaxation rate for a commonly used spherical vapor cell is derived, revealing the intrinsic correlation among cell size, atomic spin relaxation, and optimal pressure. Based on the theoretical model, the filling parameters of the vapor cell are optimized, and experimental measurements are carried out. The theoretical relaxation results are highly consistent with the experimental ones, realizing the precise optimization of buffer gas pressure. The optimization method proposed in this paper provides a theoretical basis and parameter guidance for the engineering preparation of alkali-metal vapor cells for high-sensitivity SERF magnetometers in remote sensing applications.