The negatively charged nitrogen-vacancy (NV) color center in diamond exhibits several remarkable properties, which make it widely used in magnetic field sensing. In this paper, we present a miniaturized fiber-integrated chip-scale diamond magnetometer. The diamond sensor utilizes an optical fiber for side excitation to enhance fluorescence collection efficiency and subsequently integrates a microwave antenna and photodiodes on-chip. By coating the metal oxide dielectric film on the diamond surface, the green pump light can be filtered out. The implementation of the Ramsey sequence enhances sensitivity while suppressing microwave crosstalk in photovoltaic devices. The volume of the final sensing area is less than 6 mm 3 , and the magnetic field detection sensitivity of 150 nT/ Hz is achieved. This sensor supports various practical applications, including microwave probing, energy monitoring, power systems, and non-destructive testing, while enabling a millimeter-scale standoff distance from the sensing region.
Liu et al. (Fri,) studied this question.