Magnetic field imaging with microfabricated optically-pumped magnetometers

Area of Science:

• Physics
• Instrumentation
• Magnetometry

Background:

• Accurate magnetic field measurement is crucial for various scientific and technological applications.
• Existing magnetic field sensors face limitations in sensitivity, spatial resolution, or power consumption.

Purpose of the Study:

• To develop and characterize a novel multichannel imaging system using microfabricated optically-pumped magnetometers.
• To demonstrate the system's capability for high-resolution magnetic field imaging.

Main Methods:

• A 25-sensor array of microfabricated optically-pumped magnetometers was fabricated with small sensor probes (< 1 cm²).
• The sensor array was operated at low ambient magnetic fields and in Earth's magnetic field.
• Magnetic field imaging was performed using the sensor array to map fields from small probe coils.

Main Results:

• The sensor array achieved an average magnetic sensitivity of 24 fT/Hz^1/2 in low fields and 5 pT/Hz^1/2 in Earth's field.
• Individual sensor heads consumed low power (76 ± 7 mW) and had a sensitive volume of 1.5 mm³.
• Magnetic field imaging results showed good agreement with expected field patterns.

Conclusions:

• The developed multichannel imaging system offers high magnetic sensitivity and spatial resolution.
• This technology is suitable for detailed magnetic field mapping applications.
• The compact and low-power design of the sensors enables versatile deployment.