Seminarium Optyczne

When increasing the intensity of optical pulses we can probe different regimes of laser-matter interactions. Specifically, in the area of strong-field physics we deal with bound electrons that undergo various atomic transformations due to the interaction with the laserfield. The theoretical framework behind is non-relativistic quantum mechanics, based on the time-dependent Schrodinger equation. Going toward higher intensities, we reach the ultra-strong-field regime. Here,we deal with free electrons whose quiver energy in a laser field becomes comparable to their rest mass energy. Thus, we enter the area governed by relativistic quantum mechanics, that is based on the Dirac equation. The physics in those two regimes has to be treated using different theoretical methods and inherently different physical effects should be observed there. But is it always the case? In my talk, I will address this question considering two seemingly different physical processes, representing each of those regimes: ionization and electron-positron pair creation.