This paper reports on the electrical characterization of the first prototypes of Geiger-Mode Avalanche Photodiodes (GM-APDs) and Silicon Photomultipliers (SiPMs) produced at ITC-irst, Trento. Both static and functional measurements have been performed in dark condition. The static tests, consisting in reverse and forward IV measurements, have been performed on 20GM-APDs and 90 SiPMs. The breakdown voltage, the quenching resistance value and the current level have been proved to be very uniform. On the other hand, the analysis of the dark signals allowed the extraction of important properties such as the dark count rate, the gain, the after-pulse and optical cross-talk (in case of the SiPMs) rates. These parameters have been evaluated as a function of the bias voltage, showing trends perfectly compatible with the theory of the device

A 64-pixel linear array aimed at 3-D vision applications is implemented in a high-voltage 0.8 mum CMOS technology. The detection of the incident light signals is performed using photodiodes biased above breakdown voltage so that an extremely high sensitivity can be achieved exploiting the intrinsic multiplication effect of the avalanche phenomenon. Each 38times180-mum² pixel includes, besides the single photon avalanche diode, a dedicated read-out circuit for the arrival-time estimation of incident light pulses. To increase the distance measurement resolution a multiple pulse measurement is used, extracting the mean value of the light pulse arrival-time directly in each pixel; this innovative approach dramatically reduces the dead-time of the pixel read-out, allowing a high frame rate imaging to be achieved. The sensor array provides a range map from 2 m to 5 m with a precision better than plusmn0.75% without any external averaging operation. Moreover, with the same chip, we have explored for the first time the implementation of an indirect time-of-flight measurement by operating the proposed active pixel in the photon counting mode