Direct measurement of fluorescence lifetime using high speed data acquisition
Time-correlated single photon counting (TCSPC) is commonly used to measure the lifetime of fluorescence from dye molecules. In TCSPC, the sample is excited by a pulsed laser and the arrival time of each of the emitted photons at the detector relative to a trigger is recorded. An important criterion of the technique is that the excitation intensity of the laser has to be low enough such that the de