Laser-induced stresses in coated and uncoated targets

Abstract

A number of experiments were conducted with a pulsed Nd:glass laser to assess the effect of thin coatings with varying optical properties on laser coupling and stress wave generation in aluminium targets. The coatings included liquid cement, which is transparent at 1.06 mu m; Aquadag which is opaque; and silver paint, which ranges from translucent to opaque, depending upon the curing time. Considerable stress enhancement was found for the transparent plasma-confining coatings and the partially cured silver paint, which was semitransparent and contained a volatile binder. Stress levels for untreated aluminium and samples with Aquadag or cured silver paint coatings varied approximately with the coupling coefficient for these materials. The potential ramifications of these results to laser-fusion experiments are discussed.