Fibre-Coupled GaSb Quantum Dot Tuneable Single-Photon Sources for Field Deployed Quantum Key Distribution

Quantum cryptography based on single photons theoretically enables ultimate security in contrast to the classical cryptography based on mathematical complexity. An ideal single-photon source for this purpose would emit triggered photons into an optical fiber. This can be achieved using semiconductor quantum dots as the photon source. However, the current state-of-the-art quantum dot sources are not wavelength-compatible with the fiberoptic telecommunication infrastructure. The goal of the FiGAnti project is to develop GaSb based quantum dots emitting at 1.5 µm and exploit them as high-performance fiber-coupled single-photon sources. These new quantum sources will be benchmarked against the commercially available quantum key distribution technology in a deployed fiber network. The research is carried out in an international consortium including leading groups of semiconductor quantum dot device and quantum photonics from Germany, France, Poland, and Sweden.