We demonstrate a large grid of individually addressable superconducting
single photon detectors on a single chip. Each detector element is fully
integrated into an independent waveguide circuit with custom functionality at
telecom wavelengths. High device density is achieved by fabricating the
nanowire detectors in traveling wave geometry directly on top of
silicon-on-insulator waveguides. Our superconducting single-photon detector
matrix includes detector designs optimized for high detection efficiency, low
dark count rate and high timing accuracy. As an example, we exploit the high
timing resolution of a particularly short nanowire design to resolve individual
photon round-trips in a cavity ring-down measurement of a silicon ring
resonator.Comment: 7 pages, 7 figures, IEEE Trans. Appl. Supercond. (2013
