Sipalne in transmisijske tehnike za časovno ločljive študije z uporabo koherentnih svetlobnih virov

The ability to probe and manipulate matter on femtosecond timescales has transformed our understanding of ultrafast phenomena in magnetic, molecular, and condensed matter systems. These rapid processes governed by interactions between charge, spin, and lattice degrees of freedom hold the key to the development of next-generation technologies in information storage, spintronics, and quantum materials. However, unlocking such insights requires advanced light sources capable of delivering coherent, element-specific, and polarization-controlled pulses in the extreme ultraviolet (XUV) and soft X-ray regimes. This thesis investigates two complementary platforms that have emerged as frontiers in ultrafast science: Free-Electron Lasers (FELs) and High Harmonic Generation (HHG). FELs offer tunable, high-brilliance radiation with programmable polarization, enabling precision experiments at resonance edges of magnetic elements. HHG, on the contrary, provides laboratory-scale access to femtosecond and attosecond pulses and coherent XUV light, ideal for tabletop pump-probe studies. By combining these two platforms, this work addresses both the technical challenges and scientific opportunities in ultrafast magnetization dynamics, light-induced electronic transitions, and angular momentum exchange in light–matter interactions. The thesis focuses on source optimization strategies, and proof-of-principle experiments ranging from polarization-engineered FEL emission for magnetic dichroism to HHG-based femtosecond Magneto-Optic Kerr Effect (MOKE) and molecular spectroscopy. Through this multiscale approach, it highlights the role of tailored light sources not just as probes but as active tools for manipulating material properties on fundamental timescales. The results lay the groundwork for future studies of complex systems in non-equilibrium regimes, where the interplay of coherence, topology, and ultrafast dynamics defines new states of matter.