Thermo-mechanical surface damage initiation and growth in fused-silica 3(omega) (355 nm) optics are important performance and cost issues for high-power lasers (fluences of 4-14 J/cm²) in the few ns pulse length regime. We are working to characterize and identify the extrinsic origins of damage initiation: impurities, particulates, and manufacturing defects. We have performed a materials characterization survey approach using transmission electron microscopy to identify the chemistry and morphology of particles, and structural defects. TEM offers high chemical or elemental specificity and small analytical spot size yielding complementary materials characterization data and powerful clues to manufacturing improvements. We will report on our characterization of the near surface of one commercially manufactured fused silica optic, where the results indicate both the efficacy and potential value of this approach.

Date Published: 9 April 2002
PDF: 6 pages
Proc. SPIE 4679, Laser-Induced Damage in Optical Materials: 2001, (9 April 2002); doi: 10.1117/12.461724

Published in SPIE Proceedings Vol. 4679:
Laser-Induced Damage in Optical Materials: 2001
Gregory J. Exarhos; Arthur H. Guenther; Keith L. Lewis; M. J. Soileau; Christopher J. Stolz, Editor(s)