The fruitful association of quantum and integrated photonics holds the promise to produce, manipulate, and detect quantum states of light using compact and scalable systems. Integrating all the building-blocks necessary to produce high-quality photonic entanglement in the telecom wavelength range out of a single chip remains a major challenge, mainly due to the limited performance of on-chip light rejection filters. We report a stand-alone, telecom-compliant, device that integrates, on a single substrate, a nonlinear photon-pair generator and a passive pump rejection filter. Using standard channel-grid fiber demultiplexers, we demonstrate the first entanglement quantification of such a integrated circuit, showing the highest raw quantum interference visibility for energy-time entangled photons over two telecom-wavelength bands. Genuinely pure maximally entangled states can therefore be generated thanks to the high-level of noise suppression obtained with the pump filter. These results will certainly further promote the development of more advanced and scalable photonic-integrated quantum systems compliant with telecommunication standards.
@article{arxiv.2002.10106,
title = {High-quality photonic entanglement based on a silicon chip},
author = {Dorian Oser and Sébastien Tanzilli and Florent Mazeas and Carlos Alonso-Ramos and Xavier Le Roux and Grégory Sauder and Xin Hua and Olivier Alibart and Laurent Vivien and Éric Cassan and Laurent Labonté},
journal= {arXiv preprint arXiv:2002.10106},
year = {2020}
}