The InGaAs Single-Photon Counter is a module based on InGaAs/InP Single-Photon avalanche Diode (SPAD) for the detection of near-infrared single photons up to 1700 nm. It is available both as a gated module and a free-running one.

A standalone module is composed of :
A Detection Head (DH) which includes the SPAD, a front-end circuit for SPAD biasing and avalanche sensing, a fast circuitry for detector quenching and resetting, and some sub-circuits for signal conditioning. Two types of DH exist, the free running version and the gated mode option.
A Control Unit (CU) which contains the pulse generator (used only with gated mode detection heads), a Peltier controller, a PC communication system and the power supplies needed for biasing correctly the entire module. The same CU is able to control both gated mode and free-running DH.

Users can buy one control unit and different DHs, for example free running or gated, free space or pigtailed and then use the most suitable one for the chosen application.

All the main gate parameters (such as gate width, gate repetition frequency and external/internal trigger) and all the SPAD settings (temperature, excess bias and hold off) are user adjustable, by means of a PC interface. In this way the user is always able to set the best trade off between noise (DCR), detection efficiency (PDE) and timing resolution in order to match the requirements of the different applications. The detection head electronics guarantees a clean temporal response even with fast gate transitions.

Key Features

  • Sensitivity up to 1700 nm
  • Free space and fibre pigtailed options
  • Adjustable SPAD parameters (excess bias, temperature and hold-off)
  • Adjustable Gate settings (gate width and frequency, internal/external trigger reference) gate module only
  • Timing jitter down to less than 100 ps FWHM