Quantum multiscale modeling of electron dynamics and material properties during femtosecond laser-material interactions

The controlled, well-characterized evolution of the amplitude envelope and carrier-frequency sweep of ultrafast laser pulses permits measurement and control of quantum transitions on a femtosecond time scale. This opens new perspectives for controlling the transient localized electron dynamics, corresponding material properties and phase change mechanisms, which are critical in laser micro/nano fabrication. In this study, the first-principles calculations and plasma model are used to theoretically investigate the changes of localized transient electron dynamics and the corresponding material properties during femtosecond laser pulse trains ablation of fused silica. Theoretical results show that the electron dynamics including photon absorption, electron excitation and free electron distributions can be changed; the corresponding material properties such as thermal and optical properties can then be controlled; and hence, high quality structures can be obtained.