Strong Light Intensifications Yielded by Arbitrary Defects: Fresnel Diffraction Theory Applied to a Set of Opaque Disks

Imperfections on the surfaces of optical components can cause lots of damage to a high-power laser facility, due to the diffraction pattern they produce. However, actual defect specifications do not take this phenomenon into consideration, and so the impact is under- or possibly overestimated. The authors present a method using an old phenomenon, the Poisson spot, to explain how surface imperfections are able to generate huge light intensifications. It is found that a few simple parameters are sufficient to describe hotspot formation, and are also useful in controlling hotspot generation by considering particular phase objects.