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In this letter, we report the first resonant-cavity-enhanced single-photon avalanche diode (RCE SPAD) fabricated on a reflecting silicon-on-insulator (SOI) substrate. The substrate incorporates a two-period distributed Bragg reflector fabricated using a commercially available double-SOI process. The RCE SPAD detectors have peak photon detection efficiencies ranging from 42% at 780 nm to 34% at 850 nm and time resolution of 35-ps full-width at half-maximum. Typical dark count rates of 450, 3500, and 100 000 c/s were measured at room temperature with RCE SPADs having, respectively 8-, 20-, and 50-mum diameter. [ABSTRACT FROM PUBLISHER]

One of the main drawbacks of single-photon avalanche diode arrays is optical crosstalk between adjacent detectors. In the past, this phenomenon was basically ascribed to light propagating from one detector to another through a direct optical path. Accordingly, deep trenches coated with metal were introduced as optical isolation barriers between pixels. This solution, however, was unable to completely prevent the crosstalk. In this letter, we demonstrate that a strong contribution to optical crosstalk comes from photons reflected at the bottom of the chip. These photons can bypass trenches making them less effective. [ABSTRACT FROM PUBLISHER]