Surface deformation measurements following excimer laser irradiation of insulators

We have studied the surface deformation of polyimide and Pyrex glass samples resulting from local excitation with pulsed 193 nm excimer laser radiation. The objective is to understand the primary deformation modes characterizing the surface motion. A He-Ne probe beam was used to measure the deformation in conjunction with a fast rise time position sensitive detector. The data are compared to and found to be in agreement with a new detailed calculation. Three distinct temporal regimes are identified for the surface deformation: (1) local thermal expansion, (2) propagation of bulk and surface waves, and (3) simultaneous front and back surface motion (plate motion) for sufficiently thin samples.