Quantum Sensing with Fiber-Coupled Diamond Emitters*

Fluorescent defects in diamond are at the cutting edge of quantum sensor technology. When coupled to an optical fiber platform, in situ laser excitation and signal collection from these sensors is possible. The advent of microstructured fibers has enabled measurement modalities employing vector gradient field measurements, common-mode noise rejection, and scanning microresolution thermal and magnetic field imaging that can now be performed in environments without easy optical access.

In this work we have demonstrated microresolution quantum sensors based on diamond color-centers incorporated into microstructured optical fiber probes. These sensors are capable of in situ magnetic field and temperature measurements with 160 pT/√Hz and 25 mK/√Hz sensitivities via a variety of bias and noise-cancelling measurement modes.