Abstract

High Reflecting (HR) mirrors for the University of Rochester's upgrade to the Omega laser must withstand fluences of up to 3 joules/cm² at a wavelength of 1054nm¹ and reflect 99.5% of the incident energy at both S and P polarization's. A coating multilayer design of Ta₂O₅/SiO₂ on a Pyrex substrate was developed to meet these requirements. The overall wavefront error budget for the Omega Upgrade Laser allocated a surface figure tolerance for these HR mirror components of 1/10 wave at 1054nm. During early production the induced stress due to this HR mirror coating caused deflections of Omega mirror substrates to exceed this tolerance. Solutions to control thin film stress were found for this problem.

© 1995 Optical Society of America