Excimer laser interaction with dielectric thin films

Utilizing thermal Mirage technique, UV laser damage resistivity studies on electron beam evaporated LaF3MgF2 and Al2O3SiO2 reflecting multilayer stacks have been performed at λ =248 nm, τ =20 ns. Investigating these stacks by changing the number of (H, L) pairs, different coating properties were shown to be responsible to UV single-shot laser damage. The high damage resistivity of the Al2O3SiO2 multilayers is caused by low defect density, whereas the damage of LaF3MgF2 stacks origins from defects which are incorporated in the layers during the deposition process.