1,721,145 research outputs found
Single-Photon Avalanche Diodes for the Near-Infrared Range: detector and circuit issues
No full textRecently developed InGaAs/InP devices suitable as single-photon avalanche diodes (SPADs) in the near-infrared
range provide good detection efficiency and low time jitter, together with fairly low dark-count rate at moderately
low temperature. However, the overall performance is still severely limited by the afterpulsing effect (due to
carriers trapped in deep levels during the avalanche and later released). Experimental studies and speculations
aiming to improve the overall performance are here presented. The photon detection efficiency is characterized
and the primary dark-count rate is investigated, taking into account thermal generation in the InGaAs layer
(absorption layer) and trap-assisted tunneling in the InP layer (multiplication layer). Experimental investigations
on the afterpulsing are reported. Improvements obtainable with existing devices by selecting proper operating
conditions and circuit solutions are presented and discussed. In order to gain a better insight in the design of new
devices, the effectiveness of trapping levels as a function of their location and of the electric field distribution is
studied by computer simulation. The fundamental role played by the front-end circuits is assessed and
demonstrated, in particular as concerns picosecond photon timing for a SPAD operating in gated-mode with
ultrafast gate-on and gate-off transitions
Single-Photon Avalanche Diode Model for Circuit Simulations
No full textIn this letter, we present a detailed circuit model for single-photon avalanche diodes. The model can be implemented
in many computer aided design circuit simulation environments
and provides a representation of the detector’s behavior in
the above-breakdown (Geiger-mode) operation. The model implements the self-sustaining and self-quenching processes and
correctly characterizes the reverse current–voltage curve. We
show very good matching with experimental measurements obtained with both passive and active quenching circuits, and both
single-photon and photon burst excitations
Fast-gating of single-photon avalanche diodes with 200 ps transitions and 30 ps timing jitter
No full textWe present circuits and methods for fast-gating a silicon Single-Photon Avalanche Diode (SPAD) in order to attain wide dynamic range in the measurement of very faint and very fast optical signals. A mixed-signal amplifier comprising ECL logic and microwave components allows to achieve turn-ON and turn-OFF transition times below 200 ps and gating windows from 10 ns down to just few hundreds of picoseconds. A differential front-end electronics reads out the avalanche current pulse while rejecting spurious spikes due to the gate pulse, thus achieving a photon detection timing jitter below 30 ps. This paper describes the conceived circuit solutions, the overall instrument development and the results of its characterization and validation
Characterization of InGaAs/InP Single-Photon Avalanche Diodes
No full textImprovements on InGaAs/InP Single Photon Avalanche Diodes (SPADs) make them very promising for many NIR single-photon counting applications. In order to fully exploit such detectors, it is mandatory to operate them in optimized working conditions and in association with proper front-end electronics. New InGaAs/InP SPADs provide low dark-count rate at moderately low temperatures. They also show good photon detection efficiency and quite low time jitter in the near-infrared range. We report and compare the performance of two generations of InGaAs/InP SPADs working at 1550 nm
PERFORMANCE OF COMMERCIALLY AVAILABLE InGaAs/InP SPAD WITH CUSTOM ELECTRONICS
No full textInGaAs/InP devices suitable as Single-Photon Avalanche Diodes (SPADs) for photon counting and photon timing applications in the near-infrared provide good detection efficiency and low time jitter, together with fairly low dark-count rate at moderately low temperatures. However, their performance is still severely limited by the afterpulsing effect, caused by carriers trapped into deep levels during the avalanche current flow and later released. We present preliminary experimental characterization of recently-developed InGaAs/InP detectors that can promisingly be operated slightly cooled. We investigate the primary dark-count rate, taking into account both thermal generation in the InGaAs absorption layer and trap-assisted tunnelling in the InP multiplication layer. The fundamental role played by the front-end circuits in minimizing the effects of afterpulsing is assessed and demonstrated
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