Effect of multiple wavelengths combination on laser-induced damage in multilayer mirrors.

The damage effect of the combined irradiation of 1omega and 3omega in multilayer films was investigated. The experiments were held in both the Laser Induced Damage Threshold (LIDT) mode and the damage probability mode. Moreover, the effect of the laser pre-conditioning was also discussed. It was found that with two wavelengths illumination simultaneously, the number of the sensitive defects still govern the damage probability of the samples, and the energy absorption of the defects to pulse laser is a basic process in causing damage. Additionally, correlative theory models were built to explain the experimental results.