Multicolor-illuminated charge-state dynamics of the nitrogen-vacancy center in diamond

Abstract

Charge-state conversion has been a very useful tool for improving the performance of nitrogen-vacancy (NV) centers in diamond in many application scenarios. Lasers of different colors are employed to manipulate the NV charge, ranging from blue to infrared. Here, we focus on the study of the charge-state dynamics under illumination of multicolors and their combination with infrared (IR) light, and the results are directly presented in terms of charge-state population. It is shown that each color of light serves some kind of superiority over others in charge-state conversion and a greatly improved conversion rate can be induced by the additional IR illumination. We report that the steady-state ${\mathrm{NV}}^{\ensuremath{-}}$ population is increased up to 82% by IR light, and it presents basically the same response trend to infrared power as that of fluorescence counts. We also report a fast-oscillating fluorescence time trace by modulating the IR power. We believe that our work offers some straightforward results that might be of interest to researchers and lead to a clearer understanding of the NV charge-state dynamics.