Removal of water from a shallow bath under laser pulse irradiation

An experimental investigation was made of water removal from a shallow bath under the action of a CO₂-laser radiation pulse focused to a spot of size substantially smaller than the bath length. We showed that the specific expenditure of energy is determined by the intensity of laser radiation at the water surface for different values of the focal spot area and pulse duration. The removal dynamics was studied by single-frame photography technique. It was determined that the water is removed layerwise only from the walls of the cavern, which expands in the horizontal direction upon cessation of the radiation pulse. Two-dimensional numerical simulations were made of the water removal, and a mechanism was proposed to explain the experimentally observed removal pattern.