InGaAs/InP SPAD with improved structure for sharp timing response

We designed and fabricated a 25 μm active area diameter In_0.53Ga_0.47As/InP Single-Photon Avalanche Diode (SPAD) with improved layer structure and diffusion geometry in order to achieve good detection efficiency (~30% at 1550 nm), low afterpulsing (gate repetition frequency higher than 1 MHz) and very good timing performance (the timing response has a Full-Width at Half Maximum of about 57 ps at 9 V of excess bias and a fast tail with a time constant of about 30 ps).