Integrated quantum optics becomes a consequent tendency towards practical quantum information processing. Here, we report the on-chip generation and manipulation of photonic entanglement based on reconfigurable lithium niobate waveguide circuits. By introducing periodically poled structure into the waveguide interferometer, two individual photon-pair sources with controllable phase-shift are produced and cascaded by a quantum interference, resulting in a deterministically separated identical photon pair. The state is characterized by 92.9% visibility Hong-Ou-Mandel interference. Continuous morphing from two-photon separated state to bunched state is further demonstrated by on-chip control of electro-optic phase-shift. The photon flux reaches ~1.4*10^7 pairs nm-1 mW-1. Our work presents a scenario for on-chip engineering of different photon sources and paves a way to the fully integrated quantum technologies.
@article{arxiv.1404.0274,
title = {Reconfigurable on-chip entangled sources based on lithium-niobate waveguide circuits},
author = {H. Jin and F. M. Liu and P. Xu and J. L. Xia and M. L. Zhong and Y. Yuan and Y. X. Gong and W. Wang and S. N. Zhu},
journal= {arXiv preprint arXiv:1404.0274},
year = {2014}
}