High-Sensitivity and High-Resolution Magnetic Gradiometry and Thermometry with Nitrogen---Vacancy Diamond Tipped Fiber Probes

This talk will demonstrate the performance of our high-sensitivity and high-resolution nitrogen---vacancy diamond (NVD) gradiometer and thermometer fiber probes. By employing an optically detected magnetic resonance (ODMR) technique involving through-fiber optical interrogation and readout of an NVD on a fiber tip with fiber integrated microwave excitation, we are able to assess the temperature and field gradient environment around the probe. We use multiple probe designs to achieve gradient sensitivities of 10$^{\mathrm{-7}}$ nT/nm(Hz)$^{\mathrm{1/2}}$, resolutions of 5 microns, and millikelvin accuracies in a package amenable to in situ measurements in challenging biological environments.