Producing a heralded single photon source is critical for the future of optical quantum information science. T. Meany et al. produce a hybrid circuit which exploits high efficiency nonlinear waveguides to produce downconverted photon pairs. This is combined with linear laser inscribed circuits and high speed switches to producemultiplexed source of heralded single photons.
(Picture: T. Meany et al., 10.1002/lpor.201400027, pp. L42–L46, in this issue)