Modern-day technology relies on devices that use new materials and novel structures. Their implementation requires thorough characterization and deep understanding of the underlying physical processes, which involve complex interactions between electrons, magnetic moments, and vibrational degrees of freedom. Very often these processes occur at staggering rates that are beyond the reach of traditional electronic instruments, and approach optical frequencies. Optical spectroscopy, and in particular time-resolved laser spectroscopy, is often the only feasible method to probe them.