Exploring energy deposition of ultrashort lasers at the surface of dielectrics at the femtosecond scale

We perform high resolution pump-probe experiments to measure the magnitude and dynamics of laser energy deposition at the surface of a dielectric material irradiated by single femtosecond pulse. This knowledge of the scenario of laser energy absorption in dielectrics paves the way to smart engineering of material excitation by providing access to true high-quality machining at the sub-micron scale and with a real control of side-effects related to energy deposition. In particular, we demonstrate the existence of an optimal fluence range, in which the incident photons are utilized optimally for ablation.