Theoretical Modeling of Laser Induced Optical Degradation
Abstract
Laser irradiation of optical elements can degrade the performance of an optical system. In this report methodology has been established for predicting the system performance of an irradiated optical system. Models required to implement the methodology have been developed & improved; the models predict (1) the physical damage caused by laser irradiation, (2) the optical aberrations corresponding to the physical damage, & (3) the point spread function (or optical transfer function) for the optical system which includes the aberrations induced by laser irradiation. The optical aberrations caused by three types of physical damage have been modelled. The aberrations are represented as a local change in amplitude & phase of the light. Surface cracks effectively reduce the local transmission to zero. Exfoliation reduces the transmission slightly (approximately 0.08) but its main effect is to introduce a random phase difference between different flakes. Vaporization does not affect transmission, but it introduced potentially large phase differences over distances associated with variations in the vaporization dynamics. The point spread function has been calculated for a simple optical system which has optical aberrations produced by laser irradiation. The main features of the point spread function are (1) a central spike whose proportional to the square of the area which is not damaged, & (2) a damage halo whose width is determined by the characteristic size of the individual damage elements & whose total height is proportional to the incoherent sum of the square of the area of each damaged element.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA155302
Entities
People
- G. Weyl
- L. A. Popper
- M. G. Miller
- R. G. Root
Organizations
- Physical Sciences (United States)