LASER-GENERATED RAYLEIGH WAVE INTERACTIONS WITH SURFACE BREAKING SLOTS

An investigation of the interaction of laser-generated Rayleigh waves with surface breaking slots was undertaken. A modified Michelson interferometer was used to detect Rayleigh waves transmitted through slots ranging in depth from 1 mm to 5 mm. A consistent feature, which occurred after the transmitted Rayleigh wave was recorded for different distances of the interferometer beam from the slot. The time difference between the transmitted Rayleigh wave and this second feature was constant for a particular slot depth. A path is proposed to explain the existence of this feature and this interpretation is supported by studies of wave propagation through each component of the path. Using this path it is possible to determine slot depths from measurements of the transit time of both the transmitted Raleigh wave and this additional feature