Charge State Dynamics During Excitation and Depletion of the Nitrogen Vacancy Center in Diamond

The charge state dynamics of the nitrogen-vacancy (NV) center in diamond play a key role in a wide range of applications, yet remain imperfectly understood. Using single ps-pulses and pulse pairs, we quantitatively investigate the charge dynamics associated with excitation and fluorescence depletion of a single NV center. Our pulsed excitation approach permits significant modeling simplifications, and allows us to extract relative rates of excitation, stimulated emission, ionization, and recombination under 531 nm and 766 nm illumination. By varying the duration between paired pulses, we can also investigate ionization and recombination out of metastable states. Our results are directly applicable to experiments employing stimulated emission-depletion imaging, and can be used to predict optimal operating regimes where excitation and stimulated emission are maximized relative to charge-state-switching processes.