An Integrated Magnetometer Module With MFCs Based on Diamond NV Centers

In recent years, nitrogen-vacancy (NV) centers in diamonds have become promising solid-state magnetic sensors for applications due to their high sensitivity to magnetic fields and excellent spatial resolution at room temperature. However, the diamond magnetometer has a complex and large optical system and a microwave (MW) system, it is necessary to address the requirements of the measured environment for the small space and high sensitivity of the magnetometer in practical applications. In this article, we propose an integrated magnetometer module with magnetic flux concentrators (MFCs) shaped like the wings of an airplane. The fiber coupler, diamond, MW antenna, filters, photodetector (PD), and weak signal processing circuit are integrated into the integrated module. MFCs are also integrated to collect flux from a larger area and concentrate it into the center of the diamond magnetometer, which is used to improve the sensitivity of the diamond magnetometer. The volume of the integrated module is limited to 3.81 cm ³ and achieves the actual magnetic sensitivity of sub-0.34 nT/Hz $^{\text {1/{2}}}$ . In the designed magnetometer module, the devices are assembled more easily and tightly, which provide a new degree of freedom for the production of the diamond magnetometer.