Investigation of Wedge Waves Using Digital Shearing Speckle Interferometry

The propagation of laser-generated wedge waves in a wedge was investigated using digital shearing speckle interferometry based on a Michelson interferometer. Different from traditional measuring methods, the laser beam provides illumination on the surface of the wedge to generate wedge waves, and another laser beam was used as the probe beam. The beam that reflected from the surface passed through an interferometric setup, a Michelson interferometer that allowed imaging the out-of-plane surface displacements. From a series of interferograms taken by a charge coupled device, the propagation of wedge waves along the wedge tip could be visualized.