Principal Investigator Nuh Gedik
Pump probe spectroscopy is the simplest experimental technique used to study ultrafast electronic dynamics. In this technique, an ultrashort laser pulse is split into two portions; a stronger beam (pump) is used to excite the sample generating a non-equilibrium state and a weaker beam (probe) is used to monitor the pump-induced changes in the optical constants (such as reflectivity or transmission) of the sample. Measuring the changes in the optical constants as a function of time delay between the arrival of pump and probe pulses yields information about the relaxation of electronic states in the sample. Depending on the specific electronic excitations being studied, wavelengths of the pump and probe beams can either be the same (degenerate pump-probe) or different (non-degenerate).