Waveguide superconducting single-photon autocorrelators for quantum photonic applications

We report a novel component for integrated quantum photonic applications, a waveguide single-photon autocorrelator. It is based on two superconducting nanowire detectors patterned onto the same GaAs ridge waveguide. Combining the electrical output of the two detectors in a correlation card enables the measurement of the second-order correlation function g(2) which realizes the functionality of a Hanbury-Brown and Twiss experiment in a very compact integrated device. Each detector shows a polarization-independent quantum efficiency of ~0.5-1% at 1300 nm. This autocorrelator represents a key building block for quantum photonic integrated circuits including single-photon sources and linear optics. © 2013 SPIE.