Excitation of Surface Elastic Waves by Transient Surface Heating

The generation of surface elastic waves by the transient surface heating of piezoelectric and nonpiezoelectric solids is described. A Q‐switched ruby laser produces the surface heating; the frequencies of the resultant surface waves are Fourier components of the laser waveform. The use of a spatially periodic illumination is shown to increase the effectiveness of generation at a selected frequency. This method of generating surface waves appears suitable for microwave frequency operation as well as operation at high wave amplitudes at low frequencies.