Pulsed laser induced acoustic wave propagation and interaction in liquid: Experiment and simulation

Abstract

In-situ experimental work on laser induced pressure waves in water is presented in this paper. A double frequency Nd:YAG laser(532 nm, 4 ns pulse width) was irradiated on a chromium thin film on quartz substrate in contact with water. A plane pressure wave with high temporal and spatial resolution was generated by the laser induced thermoelastic stress around 8 similar to 12 mJ/cm(2) below the regime of shock wave generation. The pressure wave was observed to propagate at the speed of sound in water. The plane acoustic wave could be interacted and focused with solid structures. FEM numerical simulations of the aforementioned phenomena are also carried out to solve the 2D transient wave equation and compared with the experimental results.