Design Of Digital Detection Module In Optical Pumped Magnetometer

Magneto-optical double resonance is the principle of optical pumped magnetometer, which is a high-precision, high-sensitivity magnetic measuring equipment that is based on Zeeman effect, optical pumping effect and magnetic resonance effect. Compared with other types of magnetometer, optical pumped magnetometer has a significant advantage in measuring the earth’s magnetic. It has advantages such as low noise, wide measuring range, no need for low temperature environment, etc. It has already been used in many fields like geophysical exploration, astronauts, underground resources exploration, archeology and other fields. Optical pumped magnetometer can be divided into two parts:the optical system and the signal detection system. This paper mainly studied the design of the detection system, including the following:I. From the view of the physical properties of helium atoms and their interaction with light and magnetic field, a brief introduction about the principle of optical pumped magnetometer was given.II. The magnetometer’s signal characteristics were studied by using Labview simulation programs. Accordingly, the design principle of the detection system was given. In order to reduce noise in the optical pumped magnetometer, the virtual instrument technology was applied to design the signal detection module for the first time. With Labview programming tool and the PXI-Platform based control system, the integrated design of the data acquiring module, the digital signal processing module and the signal generating module were completed.III. Analysis of the three modules was performed with emphasis on the digital signal processing algorithm. By improving the structure of the low-pass filter, the system noise level was reduced with the bandwidth unchanged. Besides, by using trapezoidal integration incremental PID control algorithm, the system’s robustness and anti-interference ability were greatly improved.