32 x 32 NbN SNSPD array based on thermally coupled row-column multiplexing architecture

We report a superconducting nanowire single-photon detector (SNSPD) array aiming for a near-infrared 1550nm wavelength that consists of 32 x 32 nanowire pixels and an area of 0.96 mm x 0.96 mm. Unlike most reported large-scale SNSPD arrays with amorphous films, NbN superconducting nanowires are employed in our array, which allows the detector operation at 2.3 K provided by a compact two-stage Gifford-McMahon cryocooler. Thermally coupled row-column multiplexing is employed in our arrays to avoid current redistribution and loss of electrical signal occurring in the electrically coupled row-column architecture. The fabricated detector array shows a pixel yield of 94% and maximal intrinsic efficiencies of 77% and 96% at 1550 nm and 405 nm, respectively. The timing jitter and the thermal coupling probability are also investigated.