In this group we emphasize modelling and simulation of nanophotonic structures as well as the exploration, theoretical and experimental, of devices and structures for all-optical signal processing. Theoretically we are concerned with the development of new methods for analyzing and simulating advanced structures, in particular devices incorporating quantum dots into a photonic waveguide or cavity, e.g. realized using photonic crystal or nanowire technology. Experimentally, we use ultrafast pump-probe techniques to measure the dynamics of materials and devices down to a time scale of about 100 femtoseconds, extracting information about basic carrier dynamics and device performance at ultra-high speeds.
Slow and fast light effects in semiconductor waveguides is a major topic of investigation. At a fundamental level we aim at understanding, through experiments and modelling, the relevant physical processes in semiconductor waveguides, and next we are exploring these for various applications, in particular within microwave photonics. The dynamics of quantum dots is central to many of our activities; we study the role of the carrier dynamical processes for ultrafast devices, such as photonic crystal lasers and devices for all-optical signal processing, but also, on a more fundamental level, for the quantum coherence properties of single-photon sources. Tailoring of the electromagnetic properties of the environment embedding the active material is a related central issue, also being explored for improving the high-power 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.