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

Within the FiGAnti project we will explore a new material system for non-classical light sources operating in the telecom bands - Antimony-based QDs.

The main goal of the project is to deploy single photons from a telecom (In)GaSb/AlGaSb QD device in an existing deployed fibre link for QKD demonstration.

To achieve this goal, we will first understand the fundamental properties of the material and explore various photonic structures (circular Bragg resonators and photonic nanowire cavities) to engineer the SPS properties.

The practical relevance of our SPSs will be increased by including strain-tuning of their emission energy, charge stabilisation and fibre pigtailing to obtain identical, scalable, compact and robust sources.

Our testbed will allow us to optimise the exact transmission wavelength in view of trade-off between transmission loss and noise, and to determine the best achievable parameters using the proposed material platform. QD-based SPS will be benchmarked against commercial decoy state and discrete/continuous-variable QKD solutions.