Ultrafast processes in condensed matter
In this activity, time-resolved optical spectroscopy is employed to study the ultrafast processes that occur in condensed matter following excitation by intense, ultrashort laser pulses. Our laboratory is based on an amplified laser source which operates at a repetition rate of 1kHz, emits ultrashort light pulses centered at a wavelength of 785 nm, having < 0.8 mJ energy and 25 fs pulse duration. Taking advantage of nonlinear optical phenomena in nonlinear crystals we generate secondary optical sources via Optical Parametric Amplification. Our workstation also includes a Spatial Light Modulator in a 4f configuration for Pulse Shaping applications. The above instruments are employed to investigate ultrafast processes occurring at two fluence regimes: (i) below and (ii) above the damage/processing threshold of a certain system.
Utilizing time-resolved, pump-probe techniques we investigate the ultrafast carrier and lattice dynamics in solid state materials. Novel bulk and nanostructured materials have high priority in our research. At higher absorbed fluences leading to ablation we are interested in the fast temporal processes that occur shortly after excitation and on how we can obtain control over such primary effects in an effort to tailor the properties of the processed material. Temporal Pulse Shaping techniques allow control of the energy deposition and dissipation in the system and, therefore, are of crucial importance in this approach.