Integrated Fibre Detection Architectures for Distributed Quantum Magnetometry

Distributed magnetic sensing over large distances is of interest for a diverse range of applications including remote detection of ferrous metals, geophysics, and biosensing. Unfortunately, the capability to measure magnetic fields over large distance is unrealized. Here, we address this problem by introducing a diamond spin magnetometer directly embedded into an optical fibre alongside high-performance optoelectronic devices. Our magnetometer relies on the translation of an ensemble of nitrogen vacancy (NV) centers in micro-diamonds within a microfluidic channel. The NV’s spin-dependent fluorescence is detected by embedded Si photodiodes. This device allows for distributed magnetic field measurements along a 300 meter-long fibre with a DC sensitivity of 81 nT Hz-1/2. We will discuss next steps and the deployment of this technology.