Time-bin to Polarization Conversion of Ultrafast Photonic Qubits

TL;DR

This paper demonstrates a high-efficiency, ultrafast method to convert quantum photonic qubits between time-bin and polarization encodings, facilitating advanced quantum communication networks.

Contribution

It introduces a novel ultrafast Kerr shutter technique for converting qubit encodings with high efficiency and fidelity, enabling hybrid quantum network implementations.

Findings

Conversion efficiency of 97% achieved.

Average fidelity of 0.827+/-0.003 demonstrated.

Shutter speeds near 1 ps used for ultrafast operation.

Abstract

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 co-polarized 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 using a method that is based on an ultrafast optical Kerr shutter and attain efficiencies of 97% and an average fidelity of 0.827+/-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.