IdealPhotonics' InGaAs single-photon detector is an infrared single-photon detection device based on InGaAs/InP APD, operating in the 900-1700nm wavelength range (especially suitable for the 1550nm fiber optic communication window). It employs gated or free-running modes, achieving single-photon sensitivity in Geiger mode, but requiring cooling to below -30°C and optimization of the quenching circuit to suppress after-pulse noise. Typical applications include quantum key distribution (QKD) and fiber optic sensing.Near-infrared single-photon detection and GHz-level gated operation are also available, but cooling and a low duty cycle (<1%) limit the dynamic range.