High-speed current measurement for nitrogen-vacancy centers galvanometer utilizing adaptive frequency sweeping method

Quantum sensors based on diamond nitrogen-vacancy (NV) centers address the need for high-speed current monitoring and demonstrate significant application value for the rapidly evolving industrial electrical systems. Such sensors require frequency sweeping to acquire current information. However, conventional frequency sweeping methods used in diamond sensors suffer from redundant sampling, restricting high-speed performance. This study proposes an adaptive frequency sweeping (AFS) method integrating two synergistic protocols, including resonance peak focused sweeping (RPFS) for large range variations and adaptive resonance peak tracking (ARPT) for small range fluctuations. The AFS technique dynamically switches between RPFS and ARPT according to current variation, enabling high-speed current measurement across varying magnitudes of current change. Experimental validation demonstrates this advantage with <29 ms tracking latency for current variation rates lower than 818 A/s, and higher rates <49 ms. The AFS technique illustrates the potential application in high-power current transmission environments monitoring.