Enhancement of a silicon waveguide single photon source by temporal multiplexing

Efficient generation of single photons is one of the key challenges of building photonic quantum technology, such as quantum computers and long-distance quantum networks. Photon source multiplexing – where successful pair generation is heralded by the detection of one of the photons, and its partner is routed to a single mode output – has long been known to offer a concrete solution, with output probability tending toward unity as loss is reduced. Here, we present a temporally multiplexed integrated single photon source based on a silicon waveguide and a low-loss fibre switch and loop architecture, which achieves enhancement of the single photon output probability of $4.5\pm 0.5$, while retaining $g^{(2)}(0)=0.01$.