S. Gogoll et al., LASER-DAMAGE OF CLEAVED AND POLISHED CAF2 AT 248-NM, Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms, 116(1-4), 1996, pp. 279-283
We investigated the surface damage of CaF2 induced by irradiation with
248 nm/14 ns laser pulses. Experiments were carried out in single sho
t mode in air. The photoacoustic deflection technique was utilized for
in situ damage detection and irradiated spots were inspected by scann
ing electron microscopy. Fracture along the natural cleavage planes wa
s observed. Comparison of cleaved and polished samples in connection w
ith modelling the thermoelastic response of the crystal during damage
reveals that polishing causes enhanced surface absorption, Damage topo
graphy at the periphery of the irradiated spots was used to obtain a r
ough estimate of the temperature rise leading to fracture. Electron mi
croscopy shows surface modifications of weakly irradiated spots where
no ablation or cracking could be detected.