Scalar Magnetometry Below 100 fT/Hz^1/2 in a Microfabricated Cell

Area of Science:

• Atomic, Molecular, and Optical Physics
• Sensor Technology
• Biomedical Engineering

Background:

• Zero-field optically-pumped magnetometers offer room-temperature alternatives to superconducting sensors for detecting weak magnetic fields.
• Current microfabricated zero-field magnetometers have limitations in dynamic range and vector measurement, restricting their use to shielded environments.
• Recent advancements have enabled total-field (scalar) magnetometers with subpicotesla sensitivity.

Purpose of the Study:

• To demonstrate a novel scalar magnetometer utilizing a microfabricated cell with enhanced performance.
• To showcase a simple optical and electronic configuration suitable for dense sensor arrays.
• To explore the potential of this sensor for applications in unshielded, nonzero magnetic field environments.

Main Methods:

• Development of a compact (18 mm³) microfabricated cell operating on a single optical axis.
• Implementation of a simple optical and electronic configuration for magnetometer interrogation.
• Characterization of the magnetometer's noise floor and operational range in static magnetic fields.

Main Results:

• Achieved a noise floor of 70 fT/Hz^1/2 with the demonstrated scalar magnetometer.
• The magnetometer operates effectively over a large static magnetic field range.
• The simple design facilitates the creation of dense sensor arrays.

Conclusions:

• The developed scalar magnetometer offers a promising solution for magnetic field sensing in unshielded environments.
• Its features are suitable for miniaturized sensors in applications like magnetoencephalography (MEG) and brain-computer interfaces (BCI).
• The sensor's capabilities pave the way for advanced biomedical and technological applications.