Probing magnetic noise from portable sensor components using a zero-field optically pumped magnetometer
APS Division of Atomic, Molecular, and Optical Physics (DAMOP) Meeting (2026)
Hyeonjae Kim, Sangkyung Lee, Younghoon Lim, Sang Hyuk Hong, Taek Jeong, and Sin Hyuk Yim
Abstract
Zero-field optically pumped magnetometers (OPMs), including operation near the spin exchange relaxation-free regime, provide high magnetic-field sensitivity to detect small magnetic-field perturbations. As OPM systems are miniaturized, nearby components are placed closer to the atomic vapor cell, and even small stray magnetic fields and magnetic noise generated by individual components can degrade sensor performance. In this study, we realize a zero-field OPM system as a sensitive test platform for characterizing magnetic-field perturbations from components used in portable OPMs. Under active three-axis magnetic-field nulling inside a magnetic shield, individual optical components are positioned 3 cm above the rubidium vapor cell to evaluate their magnetic influence. For each component, magnetic noise is characterized using the amplitude spectral density of the OPM output, while the zero-field dispersion curve is used to evaluate the sensor response and the component-induced dc magnetic field along the y direction.