Measurements of photodiode parameters in the Geiger mode

This work is devoted to the problem of efficient single photon detection for quantum cryptography and number of other applications. Here we discuss the main parameters of the single photon detector and the method of its measurement. For the quantum cryptography purposes critical parameters are the signal/noise ratio and operation speed. All parameters of the detectors have been measured. An operation point was founded with signal/noise ratio and operation speed suitable for quantum cryptography.