Laser-induced damage and periodic stripe structures of a CaF2 single crystal by an ArF excimer laser

The laser-induced damage threshold of a calcium fluoride (CaF2) single crystal was obtained by a 193 nm ArF excimer laser. The damage morphology of the crystal was analyzed. The results showed that the surface of CaF2 single crystal broke along the natural cleavage plane under ArF excimer laser irradiation, some fragments fell off, and Newton's rings were observed on the curved fragments. Laser-induced periodic stripe structures (LIPSS) appeared on the surface layer beneath the fragments that peeled off. The spacing of LIPSS was measured, and the formation mechanism of LIPSS was analyzed based on the interference model.