Atomic magnetometers with magnetic field modulation have emerged as pivotal sensors for biomagnetic measurements. However, challenges such as crosstalk between adjacent modulation fields and the complexity of signal circuitry become increasingly serious in the development of array-based equipment with the magnetometers, especially in the miniaturized atomic magnetometer. This paper proposes an all-optical, fully integrated fiber-coupled atomic magnetometer that employs pump beam modulation. A miniaturized atomic magnetometer with a volume of 10 cm³ has been designed, incorporating an active measurement area of 3 × 3 × 3 mm3. The magnetometer operates in the spinexchange relaxation-free (SERF) regime with an 87Rb vapor cell. An amplitude-modulated pump beam directly modulates the rubidium atomic ensembles, rather than the magnetic field modulation. The optical rotation angle is detected by an unmodulated probe beam oriented orthogonally to the pump beam. In light of the discontinuous pumping characteristics, we developed a modified theoretical model to clarify the output response of the proposed atomic magnetometer. The experimental results demonstrate that the new design achieves the same sensitivity as conventional magnetometer configurations with a smaller volume and without crosstalk of the magnetic field. This research highlights the significant potential for advancing the development of highly sensitive, miniaturized atomic magnetometers, making them particularly suitable for applications in magnetocardiography (MCG) and magnetoencephalography (MEG).Atomic magnetometers with magnetic field modulation have emerged as pivotal sensors for biomagnetic measurements. However, challenges such as crosstalk between adjacent modulation fields and the complexity of signal circuitry become increasingly serious in the development of array-based equipment with the magnetometers, especially in the miniaturized atomic magnetometer. This paper proposes an all-optical, fully integrated fiber-coupled atomic magnetometer that employs pump beam modulation. A miniaturized atomic magnetometer with a volume of 10 cm³ has been designed, incorporating an active measurement area of 3 × 3 × 3 mm3. The magnetometer operates in the spinexchange relaxation-free (SERF) regime with an 87Rb vapor cell. An amplitude-modulated pump beam directly modulates the rubidium atomic ensembles, rather than the magnetic field modulation. The optical rotation angle is detected by an unmodulated probe beam oriented orthogonally to the pump beam. In light of the discontinuous pumping characteristics, we developed a modified theoretical model to clarify the output response of the proposed atomic magnetometer. The experimental results demonstrate that the new design achieves the same sensitivity as conventional magnetometer configurations with a smaller volume and without crosstalk of the magnetic field. This research highlights the significant potential for advancing the development of highly sensitive, miniaturized atomic magnetometers, making them particularly suitable for applications in magnetocardiography (MCG) and magnetoencephalography (MEG).

Advanced Sensor Systems and ApplicationsOct 11, 20240 citations

Research progress on high-sensitivity chip-scale atomic magnetometers

Hao Liu, liu lin, Xiaodong Han +1 more

As one of the fundamental properties of matter, magnetic fields have extensive application value in fields such as military, medical, and industrial sectors. High-sensitivity magnetic field measurement technology is crucial for exploring the physical world, ensuring national security, and promoting industrial development. Traditional magnetic sensors based on classical physics principles, such as fluxgate and Hall effect sensors, have become increasingly difficult to meet growing demands in terms of sensitivity, volume, and power consumption. In contrast, atomic magnetometers based on quantum effects utilize the interaction between atomic spins and external magnetic fields for measurement, offering advantages such as high sensitivity, no requirement for cryogenic cooling, and the capability for absolute measurement, making them a novel type of magnetic sensor that has received significant attention in recent years. In particular, the development of chip-scale atomic magnetometers, through technologies such as Micro-Electro-Mechanical Systems (MEMS), has significantly reduced the volume and power consumption of atomic magnetometers, enabling them to demonstrate tremendous application potential in fields such as ocean exploration, biomedical applications, and geological exploration. This paper will review the technological advances of high-sensitivity chip-scale atomic magnetometers, with a focus on discussing the latest achievements in their miniaturization and small-scale research.As one of the fundamental properties of matter, magnetic fields have extensive application value in fields such as military, medical, and industrial sectors. High-sensitivity magnetic field measurement technology is crucial for exploring the physical world, ensuring national security, and promoting industrial development. Traditional magnetic sensors based on classical physics principles, such as fluxgate and Hall effect sensors, have become increasingly difficult to meet growing demands in terms of sensitivity, volume, and power consumption. In contrast, atomic magnetometers based on quantum effects utilize the interaction between atomic spins and external magnetic fields for measurement, offering advantages such as high sensitivity, no requirement for cryogenic cooling, and the capability for absolute measurement, making them a novel type of magnetic sensor that has received significant attention in recent years. In particular, the development of chip-scale atomic magnetometers, through technologies such as Micro-Electro-Mechanical Systems (MEMS), has significantly reduced the volume and power consumption of atomic magnetometers, enabling them to demonstrate tremendous application potential in fields such as ocean exploration, biomedical applications, and geological exploration. This paper will review the technological advances of high-sensitivity chip-scale atomic magnetometers, with a focus on discussing the latest achievements in their miniaturization and small-scale research.

Sixth Symposium on Novel Optoelectronic Detection Technology and ApplicationsMay 11, 20260 citations

Experimental Investigation on a Highly Sensitive Atomic Magnetometer

李曙光, 徐云飞, 王兆英 +2 more

Chinese Physics LettersJan 1, 20091 citation

Optical Parameter Decoupling and Optimization for Elliptically Polarized Atomic Magnetometer

Yifan Yan, Shaowen Zhang, Zehua Liu +5 more

Elliptically polarized atomic magnetometers (AMs) offer high sensitivity and compactness by using a single laser beam to polarize atoms and detect optical rotation angles. However, their sensitivity advantage over optical absorption-based AMs has not been sufficiently demonstrated. This is because the optical parameters significantly affect the pumping and probing processes, leading to parameter coupling when both processes are optimized simultaneously. Such coupling presents a considerable challenge for achieving simultaneous parameter optimization, ultimately limiting the achievable sensitivity. In this study, we developed a modified input–output model for a magnetometer, based on which an optical parameter decoupling and optimization method is proposed. Our method enables us to obtain the optimal optical parameters simultaneously, including the ellipticity, intensity, and frequency of light. Consequently, a sensitivity of 6 fT/Hz1/2 was achieved using a $4\times 4\times4$ mm3 87Rb vapor cell (an effective volume of 0.027 cm3). This work offers an efficient strategy to achieve higher sensitivity using single-beam miniaturized AMs, contributing significantly to promote biomagnetism research.Elliptically polarized atomic magnetometers (AMs) offer high sensitivity and compactness by using a single laser beam to polarize atoms and detect optical rotation angles. However, their sensitivity advantage over optical absorption-based AMs has not been sufficiently demonstrated. This is because the optical parameters significantly affect the pumping and probing processes, leading to parameter coupling when both processes are optimized simultaneously. Such coupling presents a considerable challenge for achieving simultaneous parameter optimization, ultimately limiting the achievable sensitivity. In this study, we developed a modified input–output model for a magnetometer, based on which an optical parameter decoupling and optimization method is proposed. Our method enables us to obtain the optimal optical parameters simultaneously, including the ellipticity, intensity, and frequency of light. Consequently, a sensitivity of 6 fT/Hz1/2 was achieved using a$4\times 4\times4$mm3 87Rb vapor cell (an effective volume of 0.027 cm3). This work offers an efficient strategy to achieve higher sensitivity using single-beam miniaturized AMs, contributing significantly to promote biomagnetism research.

IEEE Transactions on Instrumentation and MeasurementDec 18, 202331 citations

Research on the Key Technologies of the Compact Atomic Magnetometer

孙晓洁 SUN Xiao-jie, 寇军 Kou Jun, 张笑楠 ZHANG Xiao-nan +3 more

Acta Sinica Quantum OpticaJan 1, 20181 citation

4\times 4\times4

mm3 87Rb vapor cell (an effective volume of 0.027 cm3). This work offers an efficient strategy to achieve higher sensitivity using single-beam miniaturized AMs, contributing significantly to promote biomagnetism research.