Ablation threshold and crater morphology of amorphous and crystalline SiO2 glass for extreme ultraviolet femtosecond pulses.

The ablation threshold fluence and crater morphology of amorphous and crystalline SiO₂ glass were analyzed in the regime of an extreme ultraviolet femtosecond pulse. Despite the difference between the densities (or optical penetration depths) of amorphous and crystalline SiO₂ glass, the ablation threshold fluences and crater morphologies were found to be comparable. In addition, we compared our experimental results at a 10.3 nm wavelength with those in a previous work at a 13.5 nm wavelength. We conclude that the impact of the difference in density or optical penetration depth of several tens of percent on the ablation process is limited. [ABSTRACT FROM AUTHOR]