Relevance of Carbon Dioxide Laser to Remove Scratches on Large Fused Silica Polished Optics. Issue 3 (9th December 2014)

• Record Type: Journal Article
• Authors: Cormont, Philippe; Bourgeade, Antoine; Cavaro, Sandy; Donval, Thierry; Doualle, Thomas; Gaborit, Gael; Gallais, Laurent; Lamaignère, Laurent; Rullier, Jean‐Luc
• Other Names: Willenborg Edgar guestEditor.
• Is Part Of: Advanced engineering materials. Volume 17:Issue 3(2015:Mar.)
• Page Start: 253
• Page End: 259
• Publication Date: 2014-12-09
• Subjects: Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201400383
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Scratches at the surface of fused silica optics can be detrimental for the performance of optical systems. A carbon dioxide (CO2 ) laser is an interesting tool to remove those scratches because it can melt efficiently the silica in a rapid and localized way, without generating debris. In this article, we propose a new process for optical fabrication, which uses a CO2 laser to remove scratches between polishing and finishing steps. This is a linear process with no iterative polishing operations for scratch removal. This process is applied on an optic representative of laser megajoule facility production. Indeed, we succeed in removing a 10 μm deep scratch and we demonstrate that this laser operation increases the laser damage threshold by a factor of three in fluence. Abstract : A carbon dioxide (CO2 ) laser is used to remove a long scratch on a fused silica window, which can be seen on the picture. This laser treatment is applied only locally on the scratch to melt the silica surface. After processing, the scratch is not visible anymore and the window is much more resistant to high power laser illumination.