The work of the researcher in this action was conducted through 4 work packages (WPs). WP1 comprised of 2 separate tasks, focusing on the training of the individual researcher in existing time-resolved ellipsometry of laser-excited transparent materials, as well as in modelling laser excitation using advanced multiple-rate equation models. In a second work package the researcher developed and built a novel single-shot, pump-probe imaging spectroscopy setup that can probe linear and nonlinear responses of optically excited dielectrics across a large range of wavelengths (ultraviolet – near infrared) and timescales (femto- nanoseconds), essential in the understanding of multiphoton absorption and emission processes. The researcher also discovered a second nonlinear amplification mechanism in fused silica, one of the most used optical materials, hinting at the universality of the process proposed in the action. The researcher advanced the development of ultra-thin samples, which demonstrate a new access to high-excitation regimes allowing the observation of previously un-seen dynamics on ultrashort timescales, which in-turn, provides valuable insights into conditions present in the nonlinear stimulated emission in optically excited dielectrics as well as laser-material processing. In a third work package, the researcher scoped and identified novel pathways of modelling laser excitation that can accompany future measurements on the new experimental setup.
In the fourth work package, focusing on different aspects of the development of the researcher, as well as the dissemination of results, one peer-reviewed manuscript and two conference proceedings were published, and one book chapter has been prepared and is to be published after the end of the action. The researcher presented the progress of the project at seven international conferences. Additionally, was academic independence strengthened by the lead and supervision of students, the involvement as a Co-Investigator in a research grant of the Danish Independent Research Council (DFF), that continues even after the end of the action. The researcher also got involved in teaching activities at the Department of Physics and Astronomy at Aarhus University, teaching several lectures in a Laser and Optics course and supervising several experiments in the corresponding laboratory course.
Overall, will the development of the unique experimental method to study nonlinear light-matter interaction lead to novel results and several subsequent peer-reviewed manuscripts that will be submitted and published after the end of the action due to the organic delay between the build of an experimental setup and the performing of extensive studies, as well as the impact of COVID-19 measures. It is expected that the new insights and the demonstration of the measurement technique will have a large impact in the fields of light-matter interaction, materials science, and laser-material processing, respectively.
