Isotropic and integrated optical pumping magnetometer

An optical pumping magnetometer comprising:

• a cell filled with a gas;
• a laser source emitting a light beam;
• a photodetector receiving the light beam that has passed through the cell and providing an electric signal;
• first and second coils having orthogonal axes, surrounding the cell and fed by a radiofrequency generator to generate a radiofrequency magnetic field therein;
• first regulating means receiving the electric signal and configured to regulate a frequency of the radiofrequency generator to the Larmor frequency;
• second regulating means configured to keep a direction of polarization of the light beam at an inlet of the cell orthogonal to the magnetic field to be measured;
• third regulating means configured to keep a direction of the radiofrequency field identical to the direction of polarization;
• and
• a liquid crystal polarization rotator receiving the light beam and configured to rotate a direction of polarization thereof, the polarization rotator being controlled by a control signal provided by the second regulating means.