1986-1988 Research and teaching assistant (Advisor: Prof. P. Wölfle), University of Florida, Gainesville
1988-1993 Research assistant (Advisor: Prof. R.L. Byer), Stanford University
1993-1997 Group leader (chair: Prof. J. Mlynek), Universität Konstanz
1997-1999 Lecturer (Hochschuldozent), Universität Konstanz
1999-present Chair of Experimental Physics (C4), Heinrich-Heine-Univ. Düsseldorf