System and method for time correlated multi-photon counting measurements

A measurement system for measuring luminescence characteristic properties of a fluorophore material, comprising

• a light source driving and controlling unit;
• and an excitation light source for irradiating the fluorophore material with pulses of excitation light, said light source driving and controlling unit providing a triggering signal correlated to each pulse of excitation light;
• a single photomultiplier tube (PMT), for detecting a plurality of photons emitted from the fluorophore material as result of a single pulse of excitation light, said single PMT providing an amplified output signal that represents the plurality of photons detected by the single PMT;
• means for photon timing determination coupled to receive said amplified output signal and said triggering signal, the means for photon timing determination determining for each emitted photon in the plurality of photons detected by the single PMT, a photon arrival time and providing an output of a plurality of photon arrival times, and
• means for analysing the plurality of photon arrival times, arranged to receive said plurality of photon arrival times outputted from said means from photon timing determination, and able to determine from the plurality of photon arrival times characteristic properties for the fluorophore material, wherein the photon timing determination means determines and stores a plurality of arrival time measures corresponding to a plurality of detected photons, the plurality of photons resulting from the same pulse of excitation light;
• and
• wherein said means for analysing the plurality of photon arrival times, utilises an algorithm for the determination of characteristic fluorescent properties of the fluorophore material that is based on Bayesian inference;
• and
• wherein the algorithm for the determination of characteristic luminescent properties of the fluorophore material based on the Bayesian inference includes a first time period (δ) describing a PMT dead time;
• a second time period (τ) describing blocking of the photodetector after an excitation;
• and a third time period (υ) describing the duration of recording after each excitation.