Integrated NV (nitrogen vacancy) real-time vector magnetometer with high sensitivity and wide dynamic range

In this paper, we present a real-time vector magnetic field tracking method based on nitrogen vacancy (NV) centers magnetic detection technique. By combining optical detection magnetic resonance (ODMR) spectroscopy with multi-channel microwave frequency modulation (FM) technology, magnetic field information for each NV axis is extracted from the fluorescence signals captured by a single photodetector (PD), followed by real-time demodulation. The real-time vector magnetic field tracking method is more than 28 times faster than the frequency hopping method. Subsequently, multi-channel feedback control is introduced to track the resonance frequency of each NV axis in real-time, enabling real-time vector tracking measurements. The experimental results show that the dynamic range of the AC magnetic field is ±148.8 µT for the X, ± 151.2 µT for the Y, and ±152.5 µT for the Z. The sensitivities are 0.93nT/Hz, 0.76nT/Hz, 0.54nT/Hz respectively, which further validated the feasibility of the method. The method has potential applications in space exploration, medical diagnosis, navigation and other fields.