A multi-encoding, multi-protocol Quantum Key Distribution transmitter

Abstract

Quantum Key Distribution is gaining momentum as a countermeasure against weak key-sharing protocols. Over the last decade, implementation of QKD systems has been growing over the world, funded by private companies and governments alike. However, many players in the field are developing their own technology, which can lead to incompatibility when communicating between different countries, for example.

This work presents a quantum key distribution transmitter which is able to encode information in both the polarisation and the time-bin/phase degrees of freedom, and can generate qubits according to several different protocols.

The transmitter can both be used in free-space and over a fibre optic link, but it is mainly designed for aircraft FSO experiments.