Laser-assisted surface modification of thin chromium films

Abstract

The objective of this work is to develop a novel process by which topographical changes are produced on a micrometer scale using a pulsed Nd:YLF laser, and to investigate the energy transfer and fluid flow phenomena involved in the process. The surface of thin chromium films is altered through the laser- induced phase transformation and fluid flow. Experimental parametric studies were conducted to correlate the laser parameters with the topography of the laser irradiated surfaces. Experimental and analytical work were also performed to study the transport phenomena involved in the process. A numerical finite element analysis was carried out to simulate the transient field variables. A nanosecond-time resolution, fast photography system was constructed to capture the phase change and the fluid flow occurring at the target surface. Comparison between the numerical and the experimental data helps to understand the mechanisms of the process as well as to develop a controlled surface modification technique. ©2004 Copyright SPIE - The International Society for Optical Engineering.