Speaker
Gianmaria Collazuol
(Scuola Normale Superiore, Pisa)
Description
Silicon photo-multipliers (SiPM) consist in matrices of tiny, passive quenched
avalanche photo-diodes connected in parallel and operated in Geiger mode.
Their capability to detect low optical photon fluxes with unprecedented
amplitude resolution and their extreme single photon timing resolution
make SiPM’s suitable for many applications. The DASIPM 1 collaboration
between the Italian institutes of INFN and ITC-irst is developing, since two
years, novel types of SiPM prototypes, which have a classical shallow
junction non-p structure but are unique in their enhanced photon detection
efficiency (PDE) for short-wavelengths and in their low cross-talk. In this
report, after discussing the relevant physics of SiPM and the measurement
of PDE, we publish for the first time the measurement of single photon
timing resolution of the DASIPM devices. The timing resolution is studied by
illuminating a single SiPM with ultra-short (∼ 70fs) and low intensity laser
pulses with fixed repetition rate and measuring the time difference between
next pulses. Low noise and ultra-fast electronics is used to amplify the SiPM
signal and sample its waveform at high rate. Optimum timing digital filtering
is adopted in order to minimize the effects of noise. Intrinsic resolution
better than 40ps is measured for typical operating conditions, with λ ∼
400nm light. The dependencies of single photon timing resolution as a
function of λ and of the bias voltage are also discussed. The measurements
are in agreement with our numerical simulations of the device.
Author
Gianmaria Collazuol
(Scuola Normale Superiore, Pisa)
