arXiv:1712.05161 · Physical review. B./Physical review. B
Nitrogen-vacancy ensemble magnetometry based on pump absorption
Sepehr Ahmadi, Haitham A. R. El-Ella, Adam M. Wojciechowski, Tobias Gehring, Jørn Bindslev Hansen, Alexander Huck, Ulrik L. Andersen
Abstract
We demonstrate magnetic-field sensing using an ensemble of nitrogen-vacancy centers by recording the variation in the pump-light absorption due to the spin-polarization dependence of the total ground-state population. Using a 532 nm pump laser, we measure the absorption of native nitrogen-vacancy centers in a chemical-vapor-deposited diamond placed in a resonant optical cavity. For a laser pump power of 0.4 W and a cavity finesse of 45, we obtain a noise floor of $\ensuremath{\sim}100 \mathrm{nT}/\sqrt{\mathrm{Hz}}$ spanning a bandwidth up to 125 Hz. We project a photon shot-noise-limited sensitivity of $\ensuremath{\sim}1 \mathrm{pT}/\sqrt{\mathrm{Hz}}$ by optimizing the nitrogen-vacancy concentration and the detection method.