An integrated active-quenching circuit for single-photon avalanche diodes

We introduce the first integrated active quenching circuit (I-AQC) that dri ves an avalanche photodiode (APD) above its breakdown voltage, in order to detect single photons, Based on the I-AQC, we developed a compact and versa tile photon-counting module suitable for applications in which very weak op tical signals have to be detected, as for instance, photon correlation spec troscopy, luminescence measurements, and laser ranging, The prototype photo n-counting module features quenching pulses up to 60 V amplitude, minimum d ead time of less than 36 ns, corresponding to a saturated counting rate exc eeding 25 Mcounts/s, user-controllable hold-off time, for reducing the afte r pulsing effect, and nanosecond gating capability. The power dissipation i s 60 mW in stand-by conditions, and the module size is less than 1 cm x 2 c m.