Statistical distribution of laser damage and spatial scaling law for a model with multiple defects cooperation in damage

A simple model is proposed, featuring cooperation of many defects to the damage process. For identical, randomly and independently distributed defects, the response of the optical component to a spatially gaussian laser pulse is calculated. The absorption response of the component is a probability distribution, which depends on the values of mean defect density and beam equivalent area. For a damage threshold expressed as a value of the absorbed energy, the statistical distribution of damage is obtained theoretically, as a function of fluence. The damage fluence distribution resembles the lognormal function found in many recent experimental measurements. Damage statistics were also calculated for a diverse spatial dimensions of the beam. This cooperative model of damage is compared to the description of defect-related damage developed in particular by Mike Felt et al to correlate small beam damage tests to large area irradiation results. In the latter work, defects react one by one, contrary to the present view.