Compact multi-channel optically pumped magnetometer for bio-magnetic field imaging

Gradient phase and amplitude errors in atomic magnetic gradiometers for biomagnetic imaging systems

“…Our experimental measurement based on our self-designed compact four-channel OPM sensor with high spatial resolution, similar to the work reported in, 38 as shown in Figure 1 A. The sensor has a compact volume of only 18 cm 3 .…”

“…Moreover, the residual magnetic field in the propagation axis of the laser of each OPM was adjusted using the host computer of the control system. 38 As the response signals of each OPM are processed by a signal processing system with identical models and configurations, the phase delay introduced by the signal processing system remains the same for each OPM. The impact of the signal processing system on the results of gradient difference can be ignored.…”

Recent Developments in Fabrication Methods and Measurement Schemes for Optically Pumped Magnetic Gradiometers: A Comprehensive Review

“…Sulai et al demonstrated another, similar scheme later, with a baseline of 4 cm in a magnetically shielded room (MSR), for fetal magnetocardiography using two vapor cells and orthogonal beams [ 34 ]. Ziqi Yuan has designed a compact four-channel, single-beam, parametric-modulated, optically pumped gradiometer with a baseline of 1.5 cm, the scheme of which is shown in Figure 3 b [ 35 ]. Joonas Iivanainen et al have proposed an array of optically pumped magnetometers for magnetoencephalography, with static and dynamic noise signals measured with reference sensors and fed back to an active three-axis magnetic compensation system [ 36 ].…”

“… ( a ) Scheme of a SERF gradiometer where four magnetometers are symmetrically located in the plane of a single feedback field coil [ 33 ]; ( b ) scheme of a four-channel gradiometer using parametric modulation measurement [ 35 ]. …”

Performance optimization of a SERF atomic magnetometer based on flat-top light beam

“…[7][8][9] Currently, SERF magnetometers have transitioned from laboratory settings to practical applications such as magnetocardiography (MCG) and magnetoencephalography (MEG). [10][11][12][13][14] They are also expected to play a crucial role in advancing frontier scientific fields such as dark matter exploration and the search for charge-parity-time violation, etc. [15,16] The most classic configuration of SERF AMs involves a dual-beam configuration with orthogonal pump and probe light.…”