Development Of Miniaturized Spin-exchange Relaxation-free Atomic Magnetometer

The fundamental principle of the alkali-metal atomic magnetometer is using the coherent precession of polarized atomic spins to detect the magnetic fields.The sensitivity of the spin-exchange relaxation-free(SERF)atomic magnetometer can be achieved 2aT/Hz1/2 when the influence of the spin-exchange collisions is completely eliminated in theory.The SERF atomic magnetometer has a wide range of applications,which can be used on fundamental physics research.,military field.,biomedical domain such as the detection of the magnetocardiography(MCG)and magnetoencephalography(MEG)based on the SERF atomic magnetometer.The significance and value of this application is self-evident.In this thesis we have developed a kind of miniature spin-exchange relaxation-free(SERF)atomic magnetometer,which makes the operation is easier and the equipment is more compact,and the experiment cost is much lower.The main achievements including:On the construction of optical path,comparing with the traditional atomic magnetometer with two-beam system,the miniaturized SERF atomic magnetometer only uses a single beam of light which acts as both pump and probe light.In data acquisition,we use the virtual lock-in amplifier which based on the program of the software instead of the hardware lock-in amplifier to process and collect data.In data processing,we have abandoned the traditional method of using hardware spectrum signal analyzer,but directly extract effective data and then process the data with the other software,which reduces the use of hardware instruments in the experiment.In the structure of the detector,the cubic gas cell with the size of 10*10*10 mm is used as the detection chamber.and the magnetic field is compensated by winding the square Helmholtz coil on the detector structure.The volume of the detector is reduced as a whole,and the miniaturization is further realized.