Integrated spatial multiplexing of heralded single-photon sources

• Published in: Nature communications 2013-10, Vol.4 (1), p.2582-2582, Article 2582
• Main Authors: Collins, M.J., Xiong, C., Rey, I.H., Vo, T.D., He, J., Shahnia, S., Reardon, C., Krauss, T.F., Steel, M.J., Clark, A.S., Eggleton, B.J.
• Format: Article
• Language: English
• Subjects: 639/624/1075; 639/766/400; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms3582

The non-deterministic nature of photon sources is a key limitation for single-photon quantum processors. Spatial multiplexing overcomes this by enhancing the heralded single-photon yield without enhancing the output noise. Here the intrinsic statistical limit of an individual source is surpassed by spatially multiplexing two monolithic silicon-based correlated photon pair sources in the telecommunications band, demonstrating a 62.4% increase in the heralded single-photon output without an increase in unwanted multipair generation. We further demonstrate the scalability of this scheme by multiplexing photons generated in two waveguides pumped via an integrated coupler with a 63.1% increase in the heralded photon rate. This demonstration paves the way for a scalable architecture for multiplexing many photon sources in a compact integrated platform and achieving efficient two-photon interference, required at the core of optical quantum computing and quantum communication protocols. Photonic quantum technologies will require efficient single-photon sources and spatial multiplexing has been explored as a route to achieve this. Here, the authors present a scheme to integrate several single-photon sources using spatial multiplexing for on-chip applications at telecommunications wavelengths.