Comparison of Damage and Ultrasonic Signals, Induced by Laser at Different Wavelengths, for Aluminum and Alumina Samples

A Q‐switched Nd:YAG laser was focused at a narrow line on Al and Alumina samples to induce ultrasonic waves. The stimulated surface acoustic wave was measured by a Fabry‐Perot interferometer, while the depth of the damage created in the sample was quantified by a profilometer. Similar samples of Al and Alumina were used to measure ultrasonic signals at different laser powers and wavelengths. A profilometer was then used to quantify and measure damage depths.