The objective is to investigate a process by which micrometer scale to
pographical changes are produced on thin chromium films using a pulsed
Nd:YLF laser. The surface of chromium films is altered through laser-
induced solid-liquid phase transformation and fluid flow. Experimental
parametric studies are conducted to correlate the laser parameters wi
th the topography of the laser irradiated surfaces. Experimental and a
nalytical work is also performed to study the transport phenomena invo
lved in the process. A numerical finite-element analysis is used to si
mulate the transient field variables. A nanosecond-time-resolution, fa
st photography system is constructed to capture the phase change and t
he fluid flow occurring at the target surface. The experimental and th
e numerical studies showed that the surface topography change was caus
ed by the laser-induced surface-tension-driven flow, and the recoil pr
essure due to surface evaporation had negligible effect on the topogra
phy variation. (C) 1998 Society of Photo-Optical Instrumentation Engin
eers. [S0091-3286(98)03303-0].