Laser-damage risk assessment with extreme-event statistics

Assessing the risk of laser damage to optical components for the most demanding laser architectures, producing high average and peak laser powers, is critical to the engineering of these complex systems. The existing laser-damage tests for such optical components are based on probabilistic measurements that induce laser damage in a tested sample as their central element. Such methodologies are, clearly, not optimal as they damage the very components that they test. Here, we present a theoretical framework and identify the class of physical settings in which the risks of laser-induced damage can be quantified in a nondamaging way, i.e., without damaging the tested components. We show that, with the parameters of the laser driver adjusted in such a way that laser-damage events are rare, the multipulse laser damage probability can be expressed in closed form as a function of the laser fluence and the signal-to-noise-ratio of the laser driver. Whenever these solutions can be extended to include an adequate model of laser-induced material modifications, the risks of laser damage can be evaluated without damaging tests but based solely on suitably detailed prior data on the statistics of the laser driver and the properties of light-induced material modifications. We show that, despite the wide variety of physical processes that may contribute to multipulse laser damage, the key properties of laser damage can be understood, described, and predicted using intuitive, closed-form solutions for its statistical measurables. The developed approach is shown to provide an accurate, physically insightful fit for the vast experimental data collected under varying experimental conditions, with different laser sources and different samples, including the most recent multipulse laser-damage studies for multilayer dielectric coatings designed for high-power laser beamlines. The developed framework thus provides a powerful resource for the analysis of laser damage in strong-field multipulse laser - matter interactions. Envisioned applications include, but are not limited to, the design of optical components for laser fusion technologies.