Abstract:

In the optically pumped magnetometer, the signal to noise ratio is very low when use the method of detecting Zeeman energy level transition directly. However, the detected signal to noise ratio can be greatly improved by using the technique of magnetic resonances optical detection which can transform the microwave quantum detection to the photon detection, because the energy of photon is much greater than that of microwave quantum.The method of magnetic resonances optical detection in the OPM(Optically Pumped Magnetometer) has been studied, the principles and experimental devices are discussed which includes the method of detection of cells transparency, detection of orthogonal beams, spin exchange collision and the method of pump beam modulation. The characteristics of these methods are analyzed and compared, the application and complexity are considered, and all these will provide the basis for the design of the optically pumped magnetometer.

Key words: optically pumped magnetometer(OPM), transparency, orthogonal beams, spin exchange collision, pump beam modulation