Patent ID: 7265825

Claim:
An apparatus for measuring fluorescence lifetime, comprising: a pulse laser source that generates a pulse excitation light; an optical system that irradiates a sample with the pulse excitation light; a detector which detects a fluorescence emitted from the sample, and which outputs a detection signal corresponding to the fluorescence; a measurement unit which detects, based on the detection signal, whether the fluorescence is emitted for each of a plurality of time gates starting at different times, and which measures a number of photons of the fluorescence for each time gate; a correction unit which corrects, based on a predetermined probability distribution for a probability of emitting photons, at least one of: (i) the number of photons measured by the measurement unit for each time gate, and (ii) a first ratio of the number of photons measured by the measurement unit to a predetermined number of irradiations of the pulse excitation light into a second ratio, for each time gate; and a calculation unit that calculates a fluorescence lifetime of the sample based on at least one of the corrected number of photons and the second ratio.