Research On The Key Technology Of The NV Integrated Magnetometer

Magnetic sensors based on the quantum technology have important application value inhigh-precision measurement fields due to their excellent performance,such as earth science,biomedicine,and basic physical science.Compared with other quantum magnetic measurement technologies,the nitrogen-vacancy（NV）center magnetic detection technology has excellent characteristics,such as working at room temperature,no magnetic shielding,and all-solid state,which has attracted great attention.With the continuous development of NV magnetometer research,its performance has also been continuously improved,and it has initially possessed the application ability in various practical environments.In order to speed up the application of NV magnetometers,solving the problems of its integrated design and integrated performance improvement has become one of the key research directions of many research groups at home and abroad.This paper mainly focused on the key technologies of NV magnetometer integration:light source miniaturization,optimal design of the sensitive head structure,system performance calibration,etc.In-depth research,the completed integrated NV magnetometer prototype index and the same type of magnetic intensity reported at home and abroad Comparing to the same or even advanced level.The main research contents include:1.We proposed a design technology to replace the 532 nm laser in the traditional NV magnetometer with a 520 nm laser diode,which effectively improves the stability and integration of the NV magnetometer.Compared with the NV magnetometer prototype integrated with fiber laser,the prototype integrated with laser diode has advantages in volume,integration,cost performance,and high stability.2.We optimized the structure of the NV integrated magnetometer,and completed the integrated design of diamond,optical components,microwave antennas,photodetectors and subsequent processing circuits.The NV magnetometer probe was reduced from the previous10 cm~3to 1.54 cm~3,the sensitivity is increased from 67 n T·Hz^-1/2 to 20.77 n T·Hz^-1/2,and the assembly accuracy of the integrated probe is less than 50μm,which effectively improves the system performance.3.We tested and calibrated the performance of the developed NV integrated magnetometer,and obtained the following indicators:the minimum detectable magnetic field noise spectrum at low frequency is 20.77 n T·Hz^-1/2,the shot noise is 1.43 n T·Hz^-1/2,Magnetic field measurement range is±107μT,magnetic field conversion factor is 16.88 V/T,system bandwidth is 15 Hz.On this basis,we summarized the sensitivity improvement and noise suppression methods of the magnetometer system,and have made a preliminary design for the next chip-level NV magnetometer.