Development of viscoelastic thin films to mitigate shock wave-induced laser damage in high power laser systems
Résumé
Spallation effects caused by shock waves in optical components such as those used in the Laser MegaJoule facility during laser operation can lead to material fracture. One solution could be to use a viscoelastic thin film on these fused silica components to reduce the reflection of shock waves from the rear surface, but it must have excellent optical, mechanical, and power-handling properties. Among the viscoelastic materials investigated were Nafion and polydimethylsiloxane-based ormosil, with ormosil synthesized using a sol-gel process. The materials were characterized optically and especially tested for acoustic attenuation. These materials, as thin films deposited on a fused silica substrate, were studied under shock wave propagation using the laser shock technique. Preliminary results showed that these thin films have interesting properties that could help reduce mechanical damage to optical components.