Open AccessHigh-sensitivity multi-channel probe beam detector towards MEG measurements of small animals with an optically pumped K-Rb hybrid magnetometer
Author(s) -
Kazumasa Nishi,
Yosuke Ito,
Tetsuo Kobayashi
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.001988
Subject(s) - detector , optics , sensitivity (control systems) , magnetometer , electromagnetic coil , beam (structure) , image resolution , materials science , channel (broadcasting) , temporal resolution , resolution (logic) , magnetic field , physics , electronic engineering , computer science , quantum mechanics , artificial intelligence , engineering , computer network
Multi-channel measurements with fine spatial resolution will make magnetoencephalograms (MEGs) possible with small animals using optically pumped magnetometers (OPMs). Therefore, we fabricated a 20-channel probe-beam detector that uses a K-Rb hybrid OPM to increase the spatial resolution. First, we investigated the sensitivity of the detector using the multi-channel measurements and demonstrated that the detector had a fine sensitivity (10-20 fT/Hz 1/2 at 10 Hz). Subsequently, we measured magnetic field distribution generated from a loop coil and compared those measurements with analytically calculated distributions. The measurements were in good agreement with the theoretical predictions. The experimental results indicate that our newly developed multi-channel OPM detector has sufficient performance specifications for MEG measurements.