InGaAs/InP Single-Photon Avalanche Diode With Reduced Afterpulsing and Sharp Timing Response With 30 ps Tail

In this paper, we present the design, fabrication, and experimental characterization of a new Single-Photon Avalanche Diode (SPAD) made in InGaAs/InP for photon-counting operations up to 1700 nm. Working in gated-mode at 225 K with 5 V excess bias, this detector shows very low afterpulsing, hence the hold-off time can be set as low as a few microseconds, thus allowing high photon-counting rates (towards 1 Mcps). The timing response has a full-width at half maximum of less than 90 ps and a full-width at 1/1000 of maximum of less than 450 ps, thanks to a very fast (30 ps) exponential tail, thus allowing extremely wide dynamic ranges in time-correlated single photon counting measurements. Furthermore, such InGaAs/InP SPAD shows good photon detection efficiency ( ${>}{25%}$ at 1550 nm and 40% at 1000 nm) at a moderately low dark count rate, below 100 kcps for a 25 $\mu{\rm m}$ active-area diameter detector. These good results are due to design and fabrication optimization.