Fig. 1: Circuit model for passive quenching of the single-photon avalanche photodiode (SPAD) and the experimental setup of the single-photon measurement.
From: Dynamic-quenching of a single-photon avalanche photodetector using an adaptive resistive switch
a Equivalent circuit model for passive quenching of the SPAD in series with a quenching resistor. The dashed box is the SPAD, represented by a capacitor, a resistor, a photon switch, and voltage source. b The SPAD discharge process when an avalanche is triggered by an incident photon. c Recharging process after quenching. d Single-photon detection system. Passive quenching is accomplished by connecting a SPAD and a resistor in series. A voltage source (Keithley 2400) is used to reverse bias the SPAD. The single-photon signal is generated by attenuating the optical signal from a laser diode driven by a Keysight 33600A waveform generator. The avalanche response current is determined from the voltage on a 50 Ω readout resistor and the voltage is introduced to an amplifier (Mini-circuits ZFL-1000LN+) and then into an oscilloscope (Rigol DS7024) through a bias tee (Mini-circuits ZFBT-4R2GW+).
