Time-correlated single-photon counting TCSPC method

Time-correlated single photon counting (TCSPC) [28] is one of the most sensitive methods for studying time-resolved emission. In this technique, single photon events are detected after excitation and a statistical distribution of photons representing the decay of the excited state is built up over time. 

Fluorescence decays are generally measured using the time-correlated single photon counting (TCSPC) technique [43, 44], although the phase-shift [45] method has been also used (see Chap. 14). A brief description of TCSPC apparatus with nanosecond and picosecond time resolution is given below in order to illustrate the essential components and requirements for each time resolution. 

A related experimental method is Time-Correlated Single Photon Counting (TCSPC), which generates a histogram representing the fluorescence intensity over time. This is an efficient method because it counts photons and records their arrival time, which directly represents the fluorescence decay. 

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