Open AccessFlat-response spin-exchange relaxation free atomic magnetometer under negative feedback
Author(s) -
Hyun Joon Lee,
Jae-Hyeok Shim,
Han Seb Moon,
Ki Woong Kim
Publication year - 2014
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.019887
Subject(s) - magnetometer , bandwidth (computing) , physics , magnetic field , optics , relaxation (psychology) , nuclear magnetic resonance , negative feedback , atomic physics , condensed matter physics , materials science , computer science , quantum mechanics , telecommunications , voltage , psychology , social psychology
We demonstrate that the use of negative feedback extends the detection bandwidth of an atomic magnetometer in a spin-exchange relaxation free (SERF) regime. A flat-frequency response from zero to 190 Hz was achieved, which is nearly a three-fold enhancement while maintaining sensitivity, 3 fT/Hz1/2 at 100 Hz. With the extension of the bandwidth, the linear correlation between measured signals and a magne-tocardiographic field synthesized for comparison was increased from 0.21 to 0.74. This result supports the feasibility of measuring weak biomagnetic signals containing multiple frequency components using a SERF atomic magnetometer under negative feedback.