Fig. 3: Experimental charge dynamics at various laser powers of an NV center created during growth in the phosphorus-doped diamond.
a Time trace of the fluorescence under continuous illumination of 148 nW, 636 nm resonant laser. Blinking events arise from dynamic NV charge ionization and recombination. b Histogram of a, showing a larger population of NV− (right peak) than NV0 (left peak). The solid line is a fit. c Laser power dependence of ionization rate. The circles represent experimental data and the solid line is a fit with a saturation-modified quadratic function. The saturation power is fixed as 4.5 μW in the fitting. d Laser power dependence of recombination rate. The circles are experimental data and the solid line is a linear fit according to the model. For comparison, the dashed line is a quadratic fit according to the laser power dependence for NV centers in the non-doped diamond. Each experimental data in c and d is obtained by measuring the time trace and fitting the histogram at corresponding laser power. At each laser power various time-trace measurements are performed and similar but different values of the rates are obtained. The error bars on the experimental data are from fitting and indicate the 95% confidence interval.
