On-chip quantum interference with heralded photons from two independent micro-ring resonator sources in silicon photonics

• Published in: Optics express Vol. 26; no. 16; pp. 20379 - 20395
• Main Authors: Faruque, Imad I, Sinclair, Gary F, Bonneau, Damien, Rarity, John G, Thompson, Mark G
• Format: Journal Article
• Language: English
• Published: United States 06.08.2018
• ISSN: 1094-4087; 1094-4087
• DOI: 10.1364/OE.26.020379

High visibility on-chip quantum interference among indistinguishable single-photons from multiples sources is a key prerequisite for integrated linear optical quantum computing. Resonant enhancement in micro-ring resonators naturally enables brighter, purer and more indistinguishable single-photon production without any tight spectral filtering. The indistinguisha-bility of heralded single-photons from multiple micro-ring resonators has not been measured in any photonic platform. Here, we report on-chip indistinguishability measurements of heralded single-photons generated from independent micro-ring resonators by using an on-chip Mach-Zehnder interferometer and spectral demultiplexer. We measured the raw heralded two-photon interference fringe visibility as 72 ± 3%. This result agrees with our model, which includes device imperfections, spectral impurity and multi-pair emissions. We identify multi-pair emissions as the main factor limiting the nonclassical interference visibility, and show a route towards achieving near unity visibility in future experiments.