OPTICAL PUMPING MAGNETOMETER AND MAGNETIC SENSING METHOD

摘要

An optical pumping magnetometer is provided that is capable of improving the response of the magnetometer with respect to a magnetic field that varies with a period shorter than the transverse relaxation time of electron spin of an alkali metal atom.

主权项

1. An optical pumping magnetometer for measuring a magnetic field with variation in Larmor frequency, the optical pumping magnetometer comprising:
a unit configured to irradiate a cell with circularly polarized pumping light, to produce the cell containing an alkali metal atoms and spin polarization of the alkali metal atoms in the cell; a unit configured to emit linearly polarized probe light for reading spin of the alkali metal atoms; a probe light detection system configured to detect a rotational displacement of a plane of polarization of the linearly polarized probe light; a static magnetic field application coil configured to apply a static magnetic field to the alkali metal atoms; an oscillating magnetic field application coil configured to apply an oscillating magnetic field for causing a rotational motion around the spin of the alkali metal atoms; and a unit configured to detect information including a phase difference between an output signal from the probe light detection system and a driving current input into the oscillating magnetic field application coil, wherein detuning as a difference between Larmor frequency determined from the static magnetic field and a frequency of the driving current input into the oscillating magnetic field application coil is configured to be set within a predetermined range with respect to a measured magnetic field by adjusting the static magnetic field or the oscillating magnetic field, so as to improve response of the optical pumping magnetometer.