Transmission studies of explosive vaporization of a transparent liquid film on an opaque solid surface induced by excimer-laser-pulsed irradiation

Abstract

The dynamics of the explosion of a liquid film by an ultraviolet excimer pulsed laser is studied experimentally on top of an amorphous silicon (a-Si) film deposited on fused quartz. In particular, the transient temperature as well as the nucleation of the superheated liquid at the interface for laser fluences below and above the spontaneous nucleation threshold are monitored using an optical transmission technique. Results for different pure and mixed liquids are presented for cases of different thicknesses of the a-Si film. Details for the calibration of the transmission signal to obtain the interface temperature are provided through the application of the one-dimensional diffusion model and the characteristic matrix theory using data obtained from previous steady-state experiments. The calibrated results are in reasonable agreement with the known data for superheated liquids in the literature as well as theoretical calculations. In addition, the delay times for spontaneous nucleation of the liquids are estimated to be ≲1 μs, generally comparable with those observed in droplet explosion experiments.