Pulsed 532-nm laser-induced damage thresholds of aluminum films on quartz were systematically measured for film thickness ranging from 13 to 50 nm, using simple yet reliable acoustic and optical techniques. Experimental data were found to be consistent and reproducible, and could be satisfactorily simulated by a one-dimensional heat diffusion model with a temperature-dependent absorptance. Damage thresholds measured with the acoustic probe (interpreted as evaporative events) were in the 30- to 100-mJ/cm2 range, which are about 30% higher than those measured with the optical probe (interpreted as melting events). This small difference is consistent with the temperature-dependent absorptance assumption, and helps to explain the unexpected sensitivity of the acoustic probe relative to the optical probe, especially for thicker films.
Scopus Subject Areas
- Physics and Astronomy(all)