Efficient Fluorescence Coupling Integrated Fiber Magnetometer Based on Nitrogen Vacancy Centers

A magnetic field sensor based on a fiber-optic integrated probe at the center of a nitrogen vacancy (NV) is proposed and demonstrated. Fiber optics are utilized to replace all conventional spatial optics while efficiently enabling laser excitation and fluorescence collection from diamond. Optical models were developed to study the fluorescence collection efficiency of diamond. The fiber-coupled probe was simulated and its efficiency was improved to 3.062% compared to the 0.607% fluorescence coupling efficiency of the fiber. The optical probe magnetic resonance (ODMR) phenomenon was successfully observed and significantly improved the magnetic field sensitivity to 5.3 nT/Hz
^1/2
, which proved the feasibility and performance compared with the conventional confocal NV-centered magnetometer.