Avalanche photodiode single- and several-photon detection study

The goal of presented Study is to recognize the dependences of avalanche breakdown pulses oil number of detected photons and also oil operational and quenching conditions of avalanche photodiode. The study of avalanche breakdown initiated by one or more photons simultaneously is presented. This research is based on several years experience with operation of high dynamical range photon counter based oil silicon single photon avalanche photodiode. The existing photon counters use the difference in avalanche breakdown inherently, only as a initiating signal for time delay compensation. Using obtained information we are intended to build a new version of photon counter providing more precise information about number of detecting photons or filtering detection event depending Lip selected photon number. For the first experiments has been selected silicon single photon sensitive avalanche photodiode with diameter Lip to 200 pm and very high homogeneity of active area. The detection chip was operated in a passive quenching circuit with active gating. This setup enabled us to monitor both the diode reverse current using an electrometer and avalanche current build Up using fast digitizing oscilloscope operating at the sample rate 40 Gsamples per second. As the optical signal source with near-Poisson photon number distribution the stabilized diode laser with pulse width of 42 ps at the wavelength 778 nm. The recorded avalanche buildup waveforms enable to resolve the photon number in the dynamical range 1 to 10 000 photons per pulse. The first experimental results are presented.