A model for the pulsed laser generation of ultrasound in an isotropic film on a semi-infinite substrate is presented. The model gives the time domain displacement of the system as a function of the density and mechanical properties of the film and substrate and the thermal properties of the film. The model has been verified experimentally using a 1 ns Nd:YAG laser source for acoustic wave generation and a stabilized Michelson interferometer for detection. Experimental and theoretical signals agree well for both the case of a fast layer on a slow substrate (zirconium nitride/steel) and a slow layer on a fast substrate (titanium/aluminum).
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)