Calculation of laser-induced stresses in water

Abstract

Pressure profiles in water due to absorption of CO2 laser radiation are computed using a hydrodynamic computer code incorporating thermal conductivity and an equation of state which allows vaporization. In the absence of vaporization, the numerical results agree with the analytic solution which gives a thermal-expansion pulse of a fraction of 1 kbar. At longer times, a vaporization pulse is formed which approaches 1.8 kbar in 0.3 μsec. This gives an electromagnetic-to-acoustic-energy conversion efficiency in excess of 1.3% which is an order of magnitude greater than that obtained without vaporization.