Search Results
Dynamical studies on the generation of periodic surface structures by femtosecond laser pulses
2013, Rosenfeld, A., Höhm, S., Bonse, J., Krüger, J.
The dynamics of the formation of laser-induced periodic surface structures (LIPSS) on fused silica upon irradiation with linearly polarized fs-laser pulses (50 fs pulse duration, 800 nm center wavelength) is studied experimentally using a double pulse experiment with cross polarized pulse sequences and a trans illumination femtosecond time-resolved (0.1 ps - 1 ns) pump-probe diffraction approach. The results in both experiments confirm the importance of the ultrafast energy deposition and the laser-induced free-electron plasma in the conduction band of the solids for the formation of LIPSS.
Transition from ballistic to drift motion in high-field transport in GaAs
2013, Bowlan, P., Kuehn, W., Reimann, K., Woerner, M., Elsaesser, T., Hey, R., Flytzanis, C.
With strong THz pulses, we measure ultrafast transport of electrons, holes, and an electron-hole plasma in GaAs. The transition from ballistic to drift-like transport is strongly influenced by electron-hole scattering.
Nonlinear optical mechanism of forming periodical nanostructures in large bandgap dielectrics
2013, Grunwald, R., Das, S.K., Debroy, A., McGlynn, E., Messaoudi, H.
Nonlinear excitation mechanisms of plasmons and their influence on femtosecond-laser induced sub-wavelength ripple generation on dielectric and semiconducting transparent materials are discussed. The agreement of theoretical and experimental data indicates the relevance of the model.
Ultrafast multi-electron dynamics studied with THz-field streaking
2018, Krikunova, M., Klimešová, E., Kulyk, O., Oelze, T., Schütte, B., Gebert, T., Andreasson, J., Silaev, A.A.
This article has no abstract.
Adaptive micro axicons for laser applications
2015, Wallrabe, Ulrike, Brunne, Jens, Treffer, Alexander, Grunwald, Ruediger, Bellouard, Yves
We report on the design, fabrication and testing of novel types of low-dispersion axicons for the adaptive shaping of ultrashort laser pulses. An overview is given on the basic geometries and operating principles of our purely reflective adaptive MEMS-type devices based on thermal or piezoelectric actuation. The flexible formation of nondiffracting beams at pulse durations down to a few oscillations of the optical field enables new applications in optical communication, pulse diagnostics, laser-matter interaction and particle manipulation. As an example, we show first promising results of adaptive autocorrelation. The combination of excellent pulse transfer, self-reconstruction properties and propagation invariance of nondiffracting beams with an adaptive approach promises to extend the field of practical applications significantly.