The compaction (densification) of fused silica under low fluence (< 1 mJ/cm²/pulse), long term (hundreds of millions of pulses) 193 nm irradiation has been studied. With the use of a finite element analysis, the unconstrained densification, (delta) (rho) /(rho) , is extracted from the experimentally determined wavefront distortion. We find that the densification of silica in the low fluence exposure regime corresponds to what is predicted from the behavior described by: (delta) (rho) /(rho) equals 0.000117 (NI²)^0.53 where N equals number of pulses, I equals intensity (mJ/cm²/pulse). Results are presented of high and low intensity studies that establish the utility of the above form as a predictive tool for densification in fused silica.

Date Published: 7 July 1997
PDF: 6 pages
Proc. SPIE 3051, Optical Microlithography X, (7 July 1997); doi: 10.1117/12.275970

Published in SPIE Proceedings Vol. 3051:
Optical Microlithography X
Gene E. Fuller, Editor(s)