Silicon Photonic Wires for Broadband Polarization Entanglement at Telecommunication Wavelengths

Compact and scalable sources of broadband polarization entanglement at telecommunication wavelengths will pave the way for multiuser long-distance quantum communication at enhanced data rates, but progress toward this goal has been hindered due to large birefringence in conventional silicon-on-insulator nanowaveguides. The authors theoretically demonstrate, via dispersion engineering, the successful generation of polarization-entangled photon pairs over a broad range of wavelengths. This work also provides a strategy to avoid entanglement degradation due to polarization-mode dispersion. The proposed devices will be useful building blocks for large-scale quantum communication networks.