An Integrated Magnetometer Module With MFCs Based on Diamond NV Centers

Abstract

In recent years, nitrogen vacancy (NV) centers in diamond have become a promising solid-state magnetic sensor for applications due to their high sensitivity to magnetic field and excellent spatial resolution at room temperature. However, diamond magnetometer has complex and large optical system and microwave 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 paper, we propose an integrated magnetometer module with magnetic flux concentrators (MFCs) shaped like the wings of an airplane. The fiber coupler, diamond, microwave antenna, filters, photodetector and a weak signal processing circuit are integrated in the integrated module. MFCs are also integrated to collect flux from a larger area and concentrate it into the center of diamond magnetometer, which are used to improve the sensitivity of the diamond magnetometer. The volume of the integrated module is limited to 3.81 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> and achieve the actual magnetic sensitivity of sub-0.34 nT/Hz <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/2</sup> . In the designed magnetometer module, the devices are assembled more easily and tightly, which provides a new degree of freedom for the production of diamond magnetometer.