We demonstrated an experiment of femtosecond-laser damage threshold on GaAs wafer, the damage threshold was measured from 50 to 400fs. The mechanism was discussed through injection power, pulse duration and ablation profile. The results showed that the damage threshold increased with the pulse duration, the relationship between diameter of ablation hole and laser power density was also analyzed. It was concluded that the main factor affecting the damage threshold was photon ionization and collision ionization.
Source: Chao Yang Li