Laser Interaction With a Mercury Surface

To understand better the effects produced by the interaction of pulsed laser energy with materials, an experiment was performed with a light pulse from a ruby laser and a mercury surface. No visible arc was observed with the use of a 50-joule 2.5-millisecond laser pulse; however, a mechanical impact was observed and photographed with a framing camera. From the still frames, an estimate of the impact energy was made.Several mechanisms were examined to account for the observed effect. A rapid vaporization process, producing a reaction force into the mercury surface, would seem to account for the observed phenomenon.