Kinetics and Quantum Trajectories of Luminescence Intensity of Single Color Centers in Sodium Fluoride Crystals

Single color centers in sodium fluoride crystals were studied for the first time. The quantum trajectories of the intensity of three types of luminescence centers emitting in the visible region of the spectrum were observed, one of which is the \({\text{F}}_{3}^{ + }\) center. The quantum trajectories were determined to be flickering. Their flickering is caused by transitions of the centers from the excited singlet state to the triplet state and, further, to the ground singlet state. The average lifetime of the ground triplet state of \({\text{F}}_{3}^{ + }\) centers as measured from the quantum trajectories of luminescence of single centers is 1.9 s, which coincides with the results of past measurements of the decay kinetics of triplet luminescence of an ensemble of \({\text{F}}_{3}^{ + }\) centers.