Evaluation of enhanced mirror for LMJ reflector industrial production.

The possibility of enhanced mirrors for laser megajoule reflectors has been studied, and preliminary samples have been realized with magnetron sputtering technology. Spectral measurements of improved reflectivity and cosmetics analysis are presented.

High-accuracy measurements of the normal specular reflectance.

The French Laser Megajoule (LMJ) is designed and constructed by the French Commissariat à l'Energie Atomique (CEA). Its amplifying section needs highly reflective multilayer mirrors for the flash lamps. To monitor and improve the coating process, the reflectors have to be characterized to high accuracy. The described spectrophotometer is designed to measure normal specular reflectance with high repeatability by using a small spot size of 100 mum. Results are compared with ellipsometric measurements. The instrument can also perform spatial characterization to detect coating nonuniformity.