Nonlinear ionization control by temporally shaped fs+ps double-pulse sequence on ZnO

We designed a femtosecond (fs) + picosecond (ps) double-pulse sequence by using Mach–Zehnder-like apparatus to split single 120 fs pulse into two sub-pulses, and one of them was stretched width 2 ps four-pass grating system. Through observing the ripples induced on ZnO surface, we found ionization rate appeared be higher for in which arrived first. The electron equation used calculate changes density distribution sequences with different delay times. suggest that temporally shaped fs+ps can achieve nonlinear control influence ripples.