Photonique, the manufacturer of the SiPMs adopted for this design, promises rise times <3 ns and cell recovery time <15 ns. To avoid the shaping due to Photonique-supplied amplifier, we measured the current signal directly from the SiPM illuminated by a laser diode - a device thought to have a negligibly fast response. The light source was driven with an electronic pulse barely over threshold to generate very short signals on the order of a few photons in intensity. Undoing the convolution due to the 200 MHz-bandwidth oscilloscope indeed yields a very short signal shown in the adjacent figure (smoothed and reasonably approximated by a Gaussian.) The shaping of this input signal by the modeled amplifier was then examined. | Photonique, the manufacturer of the SiPMs adopted for this design, promises rise times <3 ns and cell recovery time <15 ns. To avoid the shaping due to Photonique-supplied amplifier, we measured the current signal directly from the SiPM illuminated by a laser diode - a device thought to have a negligibly fast response. The light source was driven with an electronic pulse barely over threshold to generate very short signals on the order of a few photons in intensity. Undoing the convolution due to the 200 MHz-bandwidth oscilloscope indeed yields a very short signal shown in the adjacent figure (smoothed and reasonably approximated by a Gaussian.) The shaping of this input signal by the modeled amplifier was then examined. |