Introduction:

Contemporary laser technology has enabled production of femtosecond few-cycle laser pulses with a possibility to control the temporal shape of its electric field. Typically, such laser pulses possess complex spectral and spatial phase dependencies which has consequences for non-linear phase sensitive interactions with matter as for example transient metallization of dielectrics or high-harmonic generation. Dealing with such interactions, it is important to precisely characterize laser phases that enter the interaction. The importance of precise characterization and control of the phases rises when the laser beams are focused to tight geometries [1]. Although the phase characterization techniques exist, they are usually based on phenomena that require high pulse energies at the order of μJ [2]. With recent advances in non-linear optics there is a possibility to use a solid-state optoelectronic device to determine phase of laser field even for sub-nJ pulses opening up new possibilities of the laser phase characterization [3].

Goal:

During this doctoral research program the interaction of few-cycle laser pulses with a state-of-the-art solid-state optoelectronic device will be studied. The findings will be used to characterize the relation between temporal and geometrical phases of broadband laser pulses. Experiments and mathematical models methods will be developed to control the phase distributions and to use it in optimization of optoelectronic devices.

Training:

The doctoral candidate will learn operating ultrafast laser technology and will get familiar with fundamental techniques related to them. Amongst them one can name: Frequency resolved optical gating, photoelectron spectroscopy, non-linear optical harmonic generation, pump-probe spectroscopy. The candidate will receive a deeper insight into physics of non-linear interactions and nanofabrication technology as she/he is going to propose own optoelectronic components and use techniques to test them. Application and testing of mathematical models goes in hand with the evaluation of the experimental work, therefore the candidate will understand in detail the theoretical aspects of the studied topics as well. Overall, the candidate will have the opportunity to develop and realize own experiments in order to pursuit the set up goals which will lead to her/his independence in research.

1.         D. Hoff, M. Krüger, L. Maisenbacher, G. G. Paulus, P. Hommelhoff, and A. M. Sayler, "Using the focal phase to control attosecond processes," J. Opt. 19, 124007 (2017).

2.         A. M. Sayler, T. Rathje, W. Müller, K. Rühle, R. Kienberger, and G. G. Paulus, "Precise, real-time, every-single-shot, carrier-envelope phase measurement of ultrashort laser pulses," Opt. Lett. 36, 1–3 (2011).

3.         T. Paasch-Colberg, A. Schiffrin, N. Karpowicz, S. Kruchinin, Ö. Sağlam, S. Keiber, O. Razskazovskaya, S. Mühlbrandt, A. Alnaser, M. Kübel, V. Apalkov, D. Gerster, J. Reichert, T. Wittmann, J. V. Barth, M. I. Stockman, R. Ernstorfer, V. S. Yakovlev, R. Kienberger, and F. Krausz, "Solid-state light-phase detector," Nat. Photonics 8, 214–218 (2014).