Vector Magnetometer based on Dispersive Cavity Readout of Nitrogen Vacancies in Diamond

Vescent Photonics, LLC, (Vescent) and the Massachusetts Institute of Technology Lincoln Laboratory (MIT-LL) propose to develop a low-noise, field-deployable vector magnetometer based on the dispersive cavity readout (DCR) of nitrogen vacancy (NV) diamond.  Solid-state quantum systems based on NV-diamond centers have many intrinsic properties that make them well-suited as stable, sensitive platforms for portable quantum sensors. The proposed magnetometer takes advantage of the intrinsic stability, vector capability, and miniaturization potential of the NV-diamond solid-state quantum system while providing significant gains in magnetic sensitivity, power consumption reduction, and sensor robustness by employing a novel, non-optical readout technique developed at MIT-LL. By using a microwave readout instead of an optical readout, DCR provides unity measurement contrast, enabling orders-of-magnitude improvement in readout fidelity and measurement sensitivity. Additionally, the scaling of magnetic sensitivity with optical power used for NV state preparation is more favorable in the DCR approach, enabling the use of electrically efficient, high-optical-power LEDs with a significant reduction in size, weight, power, and cost (SWaP-C) for portable field-deployed applications.  In Phase I work, theoretical analyses and initial laboratory measurements indicate that a DCR-based NV-diamond magnetometer can meet many of the Department of Defense’s formidable program requirements for detecting slow-moving targets with weak magnetic signatures while maintaining a low overall SWaP-C. In Phase II, Vescent and MIT-LL propose a systematic research and development program that will advance the current TRL-2 laboratory setups to TRL-5 brassboard prototypes for field testing by the Navy.