Low-Frequency Current Detection via Diamond Nitrogen-Vacancy Center Quantum Sensing

This study investigates the integration and miniaturization technology of a fiber-integrated diamond NV center magnetometer based on a multimode fiber system, with a focus on the miniaturization of enabling components, including the microwave source, microwave power amplifier, and phase-sensitive detection system. By utilizing a miniaturized microwave source and power amplifier, along with a compact phase-sensitive detection board, the overall magnetometer system is miniaturized, significantly enhancing its portability and integration. In the experiments, the system demonstrated a sensitivity of 15.2 nT/Hz1/2 and a bandwidth of 32.4 kHz, meeting the demands for fast and high-precision magnetic field measurements. This research provides technical support for the miniaturization and efficiency enhancement of diamond NV center magnetometers in practical applications, facilitating the expansion of magnetic field sensor applications.