Quantum communication is based on encoding information on single photons transmitted over optical networks. The technique provides a way of distributing secret digital keys on optical networks that can subsequently be used for encrypting and authenticating data. Although the practicality of quantum communications has been demonstrated in several field trials, the range of the technique is limited to several hundred kilometres by attenuation in optical fibres. This has stimulated an interest in quantum communications between orbiting satellites and optical ground stations, as a means to extend quantum communication networks to global scale.
Demonstrations of free space quantum communications have thus far been limited to relatively low bit rates, compared to their terrestrial counterparts. This has in part been due to difficulties in modulating near infra-red components at high rates. This project will study techniques for increasing the secure key rate to approach the Mb/s values found for fibre optic systems. This will require increasing the modulation rate of lasers and modulators and reducing the timing jitter of single photon detectors.
The PhD candidate will develop QKD hardware for satellite-based QKD, in collaboration with researchers from Toshiba Europe Limited and Heriot Watt University. Particular attention will be given to the development of optimized devices for quantum random number generation and free-space quantum key distribution transmission. The candidate will implement innovative schemes for information encoding at different wavelengths, assemble devices using discrete optics and participate to the development of the control electronics. The optics to decode the encoded pulses may also be developed in the scope of the PhD project.
The candidates should hold (or expect) a first degree (min grade 2.1) in Physics, Electronic Engineering or other relevant discipline and should have solid background in optics, quantum physics and statistics.