Afterpulse Measurement And Correction In Photon Counting

In recent years, with the development of quantum information science, single photon detection has been widely used in the fields of quantum communication, molecular fluorescence lifetime measurement, single photon resource, high resolved spectrum measurement and atmosphere pollution inspection. However, single photon detector working in Geiger mode produces some counts without photon incidence, which seriously influences photon-counting measurement. These counts usually arise from dark counts and afterpulse.The main content of this thesis are:(1) Afterpulse Probability Measurement of Pulse Laser with Photon StatisticsIn experiments, we measure single photon detector's afterpulse probability by analyzing single photon detector's statistics distribution of output electronics pulse. The obtained afterpulse probability is 0.36%, which is between 4%, the probability obtained with time-resolved spectroscopy, and 3%, the typical value in the product datasheet.(2) Afterpulse Probability Measurement with Time-Resolved Spectroscopy The afterpulse probability is measured with start-stop technique. A formula isgiven out for correcting the aberrance induced by start-stop technique and dark counts. It is shown that the afterpulse probability is mainly dependent on two trap levels. The lifetimes of these two levels are 503ns and 33ns, respectively. The influence on photon-counting induced by afterpulse can be effectively reduced by choosing an appropriate width of gate signal.