  In this paper we present a novel construction of an active quenching circuit
intended for single photon detection. For purpose of evaluation, we have
combined this circuit with a standard avalanche photodiode C30902S to form a
single photon detector. A series of measurements, presented here, show that
this single photon detector has a dead time of less than 40ns, maximum random
counting frequency of over 14MHz, low after pulsing, detection efficiency of
over 20% and a good noise performance. This simple and robust active quenching
circuit can be built from of-the-shelf electronic components and needs no
complicated adjustments.
