作者: Sonny Ly , Ted A. Laurence , Nan Shen , Bill Hollingsworth , Mary Norton
DOI: 10.1364/OE.23.004074
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摘要: As applications of lasers demand higher average powers, repetition rates, and longer operation times, optics will need to perform well under unprecedented conditions. We investigate the optical degradation fused silica surfaces at 351 nm for up 109 pulses with pulse fluences 12 J/cm2. The central result is that transmission loss from defect generation a function intensity, Ip, total integrated fluence, φT, influenced by oxygen partial pressure. In 10−6 Torr vacuum, low observed increases monotonically as number pulses. intensity above 13 MW/cm2, losses decrease, are not measureable 130 MW/cm2. A physical model which supports experimental data presented describe suppression high intensity. Similar phenomena in anti-reflective sol-gel coated optics. Absorption, scattering, primary mechanism leading loss. 2.5 air, no was detected any used. find absorption layer leads less than 1 thickness, results laser-activated chemical process involving photo-reduction within few monolayers surface. competition between photo-oxidation explains measured data: reduced when either light or O2 concentration high. expect processes similar these occur other materials power applications.