M. Sc. Lars Klompmaker; AG Bayer
What is the challenge of my research project? Why am I eager to do it?
I am using a pump-probe laser system with a high pulse repetition rate of 1GHz as measurement tool to investigate nonlinear optical effects in magnetic dielectric films and wide bandgap semiconductors. The high repetition rate of the laser system allows the rapid excitation of magnetic precession on timescales faster than the decay time of the induced effects, leading to interesting resonant effects including long range phonon and magnon modes.
Why did I choose this project?
The laser system itself was a big factor in the decision, as the high repetition rate is quite unusual, leading to many interesting measurement possibilities. Also instead of using a delay line for time resolved pump-probe measurements, an interesting technique called asynchronous optic sampling (ASOPS) is used. Here, the repetition rate of two independent laser oscillators is synchronized to each other with a small offset, leading to an increasing time delay between consecutive pulse pairs, thus creating the temporal resolution. Furthermore, a 10GHz system was recently delivered, allowing even faster reexcitation of the samples and hopefully more interesting new discoveries.