We are completing a thorough expansion of the laser-induced damage-test capabilities at LLNL which allow us to conduct tests under a variety of parameter conditions. We have nine different laser systems which cover the following parameter space: LaserWavelength (nm)Max. PRF (Hz)Duration (ns)Peak Fluence (J/cm2)Reptile 11064301065Reptile 2/4532, 266101040, 25Reptile 3355101040Chameleon 31064, 532, 355, 266103> 50Chameleon 101064, 532, 355, 2661010> 50Raster Blaster106417.8860Variable Pulse Laser (VPL)1064Single shot1–100> 70Kilroy106460006510Felix350, 2481002030 We describe details of the physical configurations of the individual systems, laser and sample diagnostics, and general testing procedures and capabilities. Damage test results are presented in a companion paper at this conference — “Laser Damage Database at 1064 nm”.

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We have conducted an extensive series of laser damage measurements on highly reflective (HR) dielectric coatings which have yielded 1064-nm thresholds as high as 40 J/cm2 for 8- to 10-ns pulses at pulse-repetition frequencies (PRF) of 10 Hz. Moreover, by laser conditioning these coatings with sub-threshold pulses, the thresholds of some coatings were raised to levels exceeding 70 J/cm2. These are the highest threshold dielectric HR coatings that we have tested in this regime. The coatings were originally developed to produce HR-overcoated metal mirrors for free-electron-laser (FED applicationsat high PRF. Our tests included coatings deposited on both dielectric substrates and molybdenum (Mo) substrates. In each category we also examined coatings with a pre-coat of Mo between the substrate and the HR stack. The improved dielectric HR stacks effectively shielded the Mo from the laser irradiation so that the thresholds of virtually all Mo samples exceeded levels of the best dielectric-enhanced and dielectric-HR-coated metal mirrors we have tested to date. In addition to the low PRF measurements, we also conducted 1064-nm damage tests at 6-kHz PRF using 65-ns pulses from the Kilroy damage test facility. The coatings survived thermal loading of fluences ranging from 2 to 10 J/cm2 with respective small spot sizes on the order of 1.2 to 0.3 mm (1/e2 diameter).