<title>Electrothermal defect generation and optical damage in a transparent medium</title>

Abstract

A model description of the laser-induced free carriers influence upon the point defect generation and optical damage in the wide-gap semiconductors and dielectrics is presented. The model is based on the following assertions: (1) The defect creation probability in solid considerably increases compared with its usual temperature-fluctuation value if the free carriers are involved in defect generation process (so-called recombination-stimulated defect reactions); (2) The point defect creation in crystal resulting in energy spectrum transformation leads to free carriers generation in solid even without the lattice heating. The positive feedback between free carrier and point defect concentrations stimulates the fast increase both carrier and defect densities and under certain conditions results in optical damage of crystal. The conducted analysis makes it possible to assert that: (1) The optical damage of transparent solids is often due to the electron-stimulated defect reactions arising under the wide range of light irradiation parameters; (2) The above mentioned process of the defect generation must be taken into account in the analysis of 'accumulative effects' in low absorbing media under multiple laser action with sub- threshold intensities.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.