The Research on Non-linearity and Sensitivity of Current Sensor Based on Diamond Magnetometer

Nitrogen-vacancy (NV) center is a kind of point defect, which consist of a nitrogen atom and a vacancy distributed in diamond. Under the irradiation of 532nm laser, the NV center can emit fluorescence with 640nm∼800nm wavelength, while the intensity of fluorescence could be influenced by microwave and magnetic field. This feature can be used to realize high-precision magnetic field measurement. The NV center current sensor has the characteristics of ultrahigh precision and long-term stability, which leads to a great application potential such as current transformers. In the test, it was found that the NV center current sensor will have a non-linear effect under high current, resulting in a limitation in current sensing application. This paper simulates the non-linear response of NV current sensor, and proposes some improvement ways based on the simulation results.