Method and system of time correlated single photon counting

The present invention concerns a method (100) of Time Correlated Single Photon Counting. The method (100) is performed by a system (10) comprising a processing unit (11, 20) an excitation module (12) and a detector module (13). The method envisages that the processing unit (11,20): a. commands the excitation module (12) to emit, towards a target, a N train of LASER pulses with a predetermined repetition period; b. starts a clock at the emission of each LASER pulse, and. for each i-th instant of time measured by the clock, increments a corresponding i- th photon counter if it receives from the detector module (13) an indication of a detection of a photon during the i-th instant of time of the clock; Furthermore, the method envisages that the processing unit (11,20): d. for each i-th clock time instant, increments a corresponding i-th status counter if it verifies that the detector module (13) is able to detect a photon during the i-th clock time instant, and e. at the end of the emission of the LASER pulse N train, divides each i-th photon counter by the corresponding i-th status counter to determine a corresponding i-th correct photon counter.