Effect of the laser output characteristic for damage in dielectric thin films

Laserinduced damage thresholds (LIDT) of several kinds of optical dielectric coatings were measured using some lasers with different output characteristics. Typical damage process was discovered through microcosmic analysis of coatings. In particular, the influences of laser output characteristics on laserinduced damage statuses in coatings were investigated. It's given that a pulsed laser is easier to damage an objective than a continuouswave laser in condition of the same laser energy. However, CW laser can easily cause ablation damage in objectives by accumulation of energy．