Multi-photon interference in large multi-port interferometers is key to linear optical quantum computing and in particular to boson sampling. Silicon photonics enables complex interferometric circuits with many components in a small footprint and has the potential to extend these experiments to larger numbers of interfering modes. However, loss has generally limited the implementation of multi-photon experiments in this platform. Here, we make use of high-efficiency grating couplers to combine bright and pure quantum light sources based on ppKTP waveguides with silicon circuits. We interfere up to 5 photons in up to 15 modes, verifying genuine multi-photon interference by comparing the results against various models including partial distinguishability between photons.
@article{arxiv.1909.02975,
title = {Testing multi-photon interference on a silicon chip},
author = {Bryn A. Bell and Guillaume S. Thekkadath and Renyou Ge and Xinlun Cai and Ian A. Walmsley},
journal= {arXiv preprint arXiv:1909.02975},
year = {2020}
}