Speaker
Description
Time-resolved spectroscopy has attracted a lot of attention in the last years. Judging by the Physics nobel prizes in 1999, 2018 and 2023, ultrafast techniques based on femtosecond lasers are also still very much on the cutting edge of research. I will present the basics of femtosecond pulse generation. Crucial applications taking advantage of the highly nonlinear processes possible with high-intensity pulses will be explained. A special focus will be laid on our own research involving the workhorse of ultrafast dynamics, the pump-probe technique. We apply it, in the form of transient absorption microscopy, to look into the time-dependent behavior of strongly coupled Squaraine molecular crystals in excited states. This research involves tunable light sources, fast broadband detection and polarization-, temporally and spatially resolved measurements. A short outlook into the theory of excitonic systems will complement this experiment-focused presentation.
