Scholte Wave at Air--Metal Interface Generated by a Pulsed Disc-Like Source

The normal displacement and pressure of Scholte and Leaky Rayleigh waves at air--metal interface generated by a pulsed disc-like source are simulated theoretically by the Cagniard--de Hoop method and studied by laser ultrasound technique experimentally. It is found that the Scholte wave detected by a photorefractive interferometer is mainly contributed by the surface pressure and the Leaky Rayleigh wave is dominated by the surface displacement. It is also proven that the pulse width of these interface waves is mainly determined by the acoustic time delay on the generating source size under our experimental conditions.