In the Theory and Signal Processing group we emphasize modelling and simulation of nanophotonic structures as well as the theoretical and experimental exploration of devices and structures for all-optical signal processing. The theoretical activities include the development of new methods for analyzing and simulating advanced structures, in particular devices incorporating quantum dots into photonic waveguides or cavities. The basic carrier dynamics and device performance at ultra-high speeds (down to 100 fs) are studied experimentally using ultrafast pump-probe techniques.
Slow and fast light effects in semiconductor waveguides are investigated in order to understand the relevant physical processes and implement them in various applications, in particular within microwave photonics.
The dynamics of quantum dots is central to many of our activities. We aim to fully understand the fundamental properties of light-matter interaction in ultrafast devices, such as photonic crystal lasers and devices for all-optical signal processing, but also for the quantum coherence properties of single-photon sources.
Tailoring the electromagnetic properties of the environment embedding the active material is being explored in order to improve the properties of vertical cavity surface emitting lasers as well as the radiation pattern of nanowires.
Finally, the use of surface acoustic waves to control light propagation in nanostructured media is being pursued both experimentally and theoretically.