Optical Signal Recording

Abstract

Time-correlated single photon counting (TCSPC) measures the time of each in- dividual photon. This is a relatively complicated operation, with a correspondingly long signal processing time or „dead time“. Moreover, load-induced changes of the detector response which remain unnoticed in other techniques show up in high-resolution TCSPC results. Both the dead time and the stability of the detector response set a limit to the count rate of TCSPC. Nevertheless, advanced TCSPC devices can be operated up to count rates of several million photons per second without noticeable loss in efficiency or accuracy