Nature and Application of Laser-based 1d Linear and Nonlinear Guided Ultrasonic Waves

The propagation of wedge waves at anisotropic monocrystalline silicon edges with different symmetry properties has been studied in detail. The reduced symmetry in crystals, as compared to isotropic media, causes a number of new features, such as the existence of supersonic leaky wedge waves and tilted spatial pulse profiles. Experimental and theoretical results are presented for three different types of symmetry configurations: A wedge symmetric about its midplane, a wedge symmetric about the plane normal to its apex line, and a wedge symmetric about one of its faces. The experiments performed include accurate measurements of the phase velocity and the wave field distribution, providing information on localization and coupling of wedge waves with other elastic waves.