English
PolskiMagnetic field mapping along a NV-rich nanodiamond-doped fiber
Integration of NV─-rich diamond with optical fibers opens perspectives to collect and guide quantum information on the spin state of the NV─ defects. Sensors exploiting diamond -functionalized fibers have been demonstrated reaching sub-nT magnetic field sensitivities over localized magnetic field sources (eg. coils or permanent magnets), but their potential for distributed sensing remains unexplored. The volumetric incorporation of nanodiamond particles into the core of an optical fiber creates the possibility of developing fibers that are magnetic field-sensitive over their entire length. Theoretically, this makes distributed optical readout of small magnetic fields possible, but does not answer questions on the addressing of the spatial coordinate, i.e. the location of the magnetic field source, nor on the performance of the sensor where the NV─ fluorescence is detected at one end, thereby integrating over defects experiencing different field strength. We demonstrate such measurement of a distributed magnetic field using a fiber with the optical core functionalized with nanodiamonds. The fiber is scanned along its length by a microwave antenna travelling over 13 cm on a translation stage, whereas the NV─ fluorescence is collected at the far end of the fiber relative to the laser pump input end. Optically detected magnetic resonance spectra were recorded at the fiber output for every step of the travel, revealing the magnetic field evolution along the fiber and indicating the magnetic field source location. The simplicity of the sensor and its scaling potential would be useful for many applications, e.g. magnetic-field mapping of photonics- or spintronics-based integrated circuits.
