Pump-probe experiments are a technique used in physics and chemistry to study fast processes at the molecular or atomic level. In these experiments, a short pulse of light, known as the "pump," excites a sample, initiating a reaction or change. This is followed by a second pulse, the "probe," which measures the state of the sample after a specific time delay. By varying this delay, researchers can capture dynamic changes over time. These experiments are particularly useful for investigating phenomena such as chemical reactions, electron dynamics, and phase transitions. They provide insights into how materials respond to external stimuli, helping scientists understand fundamental processes in fields like material science and biophysics.