Colin P. Lualdi, Fumihiro Kaneda, Joseph C. Chapman and Paul G. Kwiat Heralded single-photon sources (HSPSs) via spontaneous parametric down-conversion have long served as single-photon sources in the laboratory, but their probabilistic nature makes them unsuitable for large-scale optical quantum information processing applications. We use time-multiplexing techniques to overcome this limitation by pairing an ultra-low loss, adjustable delay line with our high-efficiency HSPS generating highly indistinguishable (~90%) photons. We report our most current results and ongoing improvement efforts, which include a 66.7±2.4% presence probability of single-photon states collected into a single-mode optical fiber, a ten-fold enhancement over the non-multiplexed case.
