LIGHT-SCATTERING FROM LASER-DAMAGED SPECKLED SURFACES

Scattering from an initially plane surface of a thin Plexiglas plate d amaged by an impinging coherent light beam of a laser is considered. T he morphology and the characteristic dimensions of the damaged speckle s was studied during the evolution of the phenomenon by interferometry and the creation of diffraction patterns. The cusped interferogram cr eated by superposition of evoluting two initial diffraction patterns, created during successive damage steps, forms caustics corresponding t o hyperbolic umbilic catastrophes. An experimental study of the evolut ion of the damage phenomenon clarifies the mechanisms of elastic and p lastic deformations of the affected zone. (C) 1997 Optical Society of America.