Improved free-running InGaAs/InP single-photon avalanche diode detectors operating at room temperature

Room-temperature operation of InGaAs/InP single-photon avalanche diode detectors operating in free-running mode, with no electrical gating, is demonstrated. An improved design of device structure permitted significantly lower dark count rates than previously reported. Free-running operation at room temperature using an incident wavelength of 1550 nm gave a noise equivalent power of 1.5 10^-15 WHz^-1/2 with improved photon timing jitter.