My research interests cover several aspects of nonlinear photonics and nonlinear quantum dynamics with fundamental and applicative aspects.

Self-organization in cold and ultracold atoms due to light-mediated interactions between atoms via feedback from a single mirror is explored to study complex phases and phase transitions including supersolids. A further activity is spontaneous magnetic ordering not only of dipolar but also quadrupolar degrees of freedom and potential connections to corresponding phases in condensed matter physics. These activities have strong interdisciplinary aspects being connected to self-organization phenomena in nonequilibrium system ubiquitous in Nonlinear and Complexity Science, technology and nature.

In semiconductor lasers, I investigate their highly nonlinear dynamics, especially in vertical-cavity devices like VCSELs and VECSELs, with a focus on polarization dynamics and spintronics on the one hand and transverse mode structure and solitons on the other. This aims in particular on the understanding of the complex nonlinear processes determining (and partially limiting) the performance of semiconductor-based photonic devices and lasers, their control and the utilization of nonlinearities for applications. Recently, I became interested in thermodynamics aspects like photon condensation providing a further fruitful link between my research fields.

I studied physics at the University of Göttingen, Heriot-Watt University (Edinburgh) and the Westfälische Wilhelms-Universität Münster. There I received my Diplom in physics in 1992, my Dr. rer. nat (PhD) in 1996, and my habilitation in 2002. In 1998 and 1999 I have been working as a postdoc at the Institut Non Lineaire de Nice with a Feodor-Lynen fellowship of the Alexander von Humboldt foundation. In May 2005 I joined the Photonics Group of the Department of Physics at the University of Strathclyde, Glasgow (Scotland, UK) as a lecturer. I am Professor of Nonlinear Photonics since November 2012.