We present the design and the experimental characterization of a new InGaAs/InP single-photon avalanche diode (SPAD), with two different diameters: i) a 10 µm device, suitable for optical fiber-based quantum applications; ii) a 25 µm one, more appropriate for freespace applications. Compared to a previous generation, we improved the design of the double zinc diffusion and optimized the layer structure. We achieved low dark count rate, around 1 kcps and 4 kcps at 225 K and 5 V excess bias for 10 µm and 25 µm devices, respectively, and down to few tens of counts per seconds at 175 K for the 10 µm detector. At 5 V excess bias and 225 K temperature, both devices also show a high photon detection efficiency (33% at 1064 nm, 31% at 1310 nm and 25% at 1550 nm for the 10 µm SPAD). Afterpulsing has been measured with a custom readout integrated circuit, achieving very low probability values. Timing jitter is comparable to previous-generation devices.

We present a comprehensive simulation flow for the estimation of photon detection efficiency as a function of wavelength in InGaAs/InP single-photon avalanche diodes (SPADs) at low temperature. We introduce a joint modelling of electrical and optical properties for SPAD detectors. We also highlight how accurately different parameters have to be calibrated in order to achieve good matching between simulations and measurements.

We present an InGaAs/InP single-photon avalanche diode (SPAD) with high photon detection efficiency and low noise for fiber-based quantum optics applications. Compared to previous InGaAs/InP SPADs, the InGaAs absorption layer is thicker, to maximize the quantum efficiency. The double zinc diffusion has been adjusted to avoid premature edge breakdown, with the help of a guard ring structure. Our detector achieves a photon detection efficiency up to 50% at 1550 nm, with a dark count rate of 20 kcps and a timing jitter of ~ 70 ps (FWHM) at 225 K. Alternatively, it features a photon detection efficiency of 37% at 1550 nm, with a dark count rate of just 3 kcps and a timing jitter of ~ 100 ps (FWHM). When combined with a custom integrated circuit, afterpulsing probability is as low as few percent with a gating frequency of 1 MHz and hold-off time of few microseconds at 225 K, allowing to achieve a photon count rate of almost 1 Mcps.

We present an InGaAs/InP single-photon avalanche diode (SPAD) with 10 µm-diameter active area, designed for fiber-based quantum applications. Improved design and fabrication lead to low dark count rate (1000 cps at 225 K), 25% photon detection efficiency and 100 ps (FWHM) timing jitter.

We present a comprehensive model to estimate photon detection efficiency (PDE) of InGaAs/InP single photon avalanche diodes (SPADs) through bidimensional simulations, including the temperature dependence of both optical and electrical properties, aimed at assisting the design of enhanced-PDE detectors.