Mechanisms of Pulsed Laser Induced Damage to Optical Coatings
Abstract
Laser induced damage in optical components is the limiting factor in the design of high power lasers. This report addresses this problem with special emphasis placed on the optical coatings used upon the components. A theoretical model is developed assuming basic mechanisms which lead to damage of the coatings. Numericals results are generated which are compared with experimental data. The basic procedure applied to this problem is that of the solution of inhomogenous field equations representing classical heat and electron diffusion in solids. The technique used is integral transform mathematics. The results are supported by modeling with a numerical finite element program. Findings include several sets of scaling relations which give insight into the relationship of the damage threshold of optical coatings to the material and laser parameters involved. These are plotted versus experimental data for support of the assumed processes. The specifics of these findings include the fact that the rate at which thermal diffusion occurs in optical components is important, and that there is a fundamental difference in the damage process between oxide and fluoride coatings. In addition, basic mechanisms are suggested as the source of damage in these coatings.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1986
- Accession Number
- ADA174194
Entities
People
- Michael R. Lange
Organizations
- University of New Mexico