The encoding of quantum information in photonic time-bin qubits is apt for long-distance quantum communication schemes. In practice, due to technical constraints such as detector response time, or the speed with which copolarized time-bins can be switched, other encodings, e.g., polarization, are often preferred for operations like state detection. Here, we present the conversion of qubits between polarization and time-bin encodings by using a method that is based on an ultrafast optical Kerr shutter and attain efficiencies of 97% and an average fidelity of $0.827\pm 0.003$ with shutter speeds near 1 ps. Our demonstration delineates an essential requirement for the development of hybrid and high-rate optical quantum networks.

• Received 1 June 2017

DOI:https://doi.org/10.1103/PhysRevA.96.053812