Damage-Resistant Sol-Gel Optical Coatings for Advanced Lasers at CEL-V

The research and development program at CEA Limeil-Valenton (CEL-V) concerning the mature technology of Nd:glass high power laser to Inertial Confinement Fusion (ICF) experiments has urged us to investigate and develop highly laser damage resistant optical coatings. Among the various existing deposition techniques, we have considered, the so-called sol-gel one has revealed very attractive technical and economical features. The chemical method we have explored is quite innovative since it allows making optical thin-films with a low-temperature route, using essentially oxide-based colloidal suspensions. Up to date, we have been able to prepare onto vitreous or plastic or even crystalline substrates antireflective or highly reflective dielectric coatings that can withstand the very high fluences that should deliver the future energy-efficient lasers in the megajoule range. Depending the need, such coatings could be narrow or broadband, abrasion-resistant or also environmentally durable. The aim of this paper is to show how the sol-gel process we are currently validating at CEL-V might serve tomorrow projects such as the harnessing of fusion energy, the greatest technological challenge facing humanity, but also household article uses.