SEDL / STP / STP1028-EB / STP18567S

Influence of Post-deposition Treatment by UV Light and Oxygen (ozone) on 350 nm Damage Thresholds of SiO² Films Deposited From Sols

Thomas, I
Lawrence Livermore National Laboratory University of California, Livermore, California

Wilder, J
Lawrence Livermore National Laboratory University of California, Livermore, California

Lee, A
Lawrence Livermore National Laboratory University of California, Livermore, California

George, D
Lawrence Livermore National Laboratory University of California, Livermore, California

Pages: 3    Published: Jan 1988

Download this paper for $25 PDF (56K)          View License Agreement
Abstract

Certain multilayer porous silica AR coatings on fused silica substrates prepared by the sol-gel process have been found to have a much lower laser damage threshold than single layer coatings prepared by the same method. Treatment with UV light in the presence of oxygen (which gives ozone) at low temperature was found to restore damage thresholds to the levels found in single layers. Damage thresholds were measured at 350 nm with a 25 ns pulse for 1000 shots at 25 Hz. The effect of exposure time and other factors such as replacement of oxygen with nitrogen and vacuum are described.