Abstract
Femtosecond pulse processing enables fine processing without the thermal diffusion. In this paper we generate femtosecond pulse train beam, which has several femtosecond pulse in a few picosecond, and investigate the processing result using femtosecond pulse train beam. It is considered the coherent phonon, which is the forced lattice oscillation due to the surface electron vibration in the high electric field, is excited on the surface in the case of irradiation both the femtosecond pulse train and femtosecond single pulse. In this paper, we measure for the coherent lattice oscillation using femtosecond pulse train
