Ultrafast dynamics

The directed control of structure of the materials lies at the heart of most applications of solid state physics in technology today. There are many technological challenges in realizing the goal of understanding and controlling structure in solids. One difficulty is related to the very fast time scales involved, which comes down to a time scale in fs range. Since conventional measurement devices are not that fast, achieving 10 fs time resolution in a measurement usually requires a so-called ultrafast laser spectroscopy technique.

On the other side, ultrafast spectroscopy is absolutely necessary for the exploring chemical and photophysical molecular properties in the condensed phase where processes such as solvation, structural reorganization in the excited state(s), energy transfer and relaxation can be revealed and explained in detail. All these processes are important from a chemical, biological, medical, environmental, or engineering perspective.

We exploit both shortness of the laser pulses and spectral broadness and tunability of coherent laser sources to conduct research in broad spectral region 50 nm – ~100 mm, with time resolution below 100 fs. With short fs laser pulses almost instantaneous system excitation is possible. Upon excitation in a Pump-probe (P-p) type of measurements, one can visualize in the time domain the ultrafast processes on extremely short timescales. Such processes are e.g. motion of electrons and ions during chemical reactions and phase changes, molecular/atomic and electronic rearrangement in liquids, gases and solids.