January 22, 2020
Jasper Rödiger, research associate at the Fraunhofer Heinrich Hertz Institute HHI, completed his dissertation with the title "Time-Frequency Quantum Key Distribution: Numerical Assessment and Implementation over a Free-Space Link" at the Humboldt–Universität zu Berlin (HU Berlin) with the overall grade magna cum laude. The work was conducted in a cooperation between Fraunhofer HHI and the Nanooptik AG of the HU Berlin.
The examination board of the Faculty of Mathematics and Natural Sciences, chaired by Prof. W. Ted Masselink also consisted of Prof. Achim Peters, Ph.D. (HU Berlin) and the reviewers Prof. Dr. Oliver Benson (HU Berlin), Prof. Dr.-Ing. Ronald Freund (Fraunhofer HHI/Technische Universität Berlin), Prof. Dr. Harald Weinfurter (Ludwig-Maximilians-Universität Munich).
In his doctoral dissertation, Jasper Rödiger investigated quantum key distribution (QKD), a cryptographic procedure with which information-theoretically absolutely secure communication is possible. He investigated the so-called time-frequency protocol theoretically as well as experimentally and demonstrated QKD via a free-space optical transmission. The time-frequency protocol can be implemented with mostly standard telecommunications technology and is robust against atmospheric disturbance, which makes it particularly suitable for free-space transmission.
Jasper Rödiger started his work at the Fraunhofer HHI in 2014 and is researching quantum cryptography and free-space optical communication in the department of Photonic Networks and Systems.