Broadband Biphoton Generation and Polarization Splitting in a Monolithic AlGaAs Chip

Integrated quantum photonics is a key tool towards large scale quantum technologies. In this work we present an AlGaAs-based photonic circuit for the on-chip generation of broadband orthogonally polarized photons and the deterministic separation of the photons into separate spatial modes, facilitating their further use in protocols. We demonstrate that 85% of the pairs are deterministically separated by the chip over a full 60 nm bandwidth and we assess the chip operation in the quantum regime via a Hong-Ou-Mandel experiment displaying a raw visibility of 75.5% over the same full bandwidth