Miniature Cavity-Enhanced Diamond Magnetometer
Résumé
We present a highly sensitive miniaturized cavity-enhanced room-temperature magnetic-field sensor based on nitrogen-vacancy centers in diamond. The magnetic resonance signal is detected by probing absorption on the 1042-nm spin-singlet transition. To improve the absorptive signal the diamond is placed in an optical resonator. The device has a magnetic-field sensitivity of 28 pT/Hz, a projected photon shot-noise-limited sensitivity of 22 pT/Hz, and an estimated quantum projection-noise-limited sensitivity of 0.43 pT/Hz with the sensing volume of ∼390 μm×4500 μm2. The presented miniaturized device is the basis for an endoscopic magnetic-field sensor for biomedical applications.