Ultrafast Imaging of Optical Damage Dynamics and Laser-Produced Wave Propagation in Polymethyl Methacrylate

摘要

A high power ultrafast laser spectrometer with image acquisition capability, the picosecond microscope is used to study optical surface damage processes in a transparent polymer, polymethyl methacrylate. Optical damage is a fast, violent, inhomogeneous solid-state chemical reaction. We observe three distinct fast processes; creation and growth of a dark absorbing damage volume, the 'damage core,' creation and propagation of a hypersonic shock wave in the surrounding atmosphere, and creation of large amplitude acoustic waves which propagate outward from the core at the velocity of sound. Reprints. (RH)