Measuring the arrival times of overlapped photo-events

We have developed and tested experimentally and by computer simulations a novel method for measuring the individual arrival times of temporally non-resolved (overlapped) single-photon detector pulses in high-intensity streams. The method is based on a set of linear transformations of photo-event pulses into a deconvolution, a transformation to standardized functions, a non-linear Chi-square fitting, etc. The retrieving accuracy varies within the range of 2–4 ns at an ADC sampling interval of 50 ns. The simultaneous measurement without dead time effects of the main photon statistics distributions as the distribution of intraevent intervals and the charge distributions has been demonstrated. The method covers the intermediate scale of intensities, where other well-known techniques for processing of photo-events are ineffective. It can be effectively applied in nuclear experiments, time-resolved spectroscopy, optical remote sensing, etc.