Abstract

Waveguide devices for Controlling the path of propagation of surface acoustic waves can be created by introducing defects in a phononic crystal. Such waveguides show more complex dispersion than conventional waveguides, and are useful in applications such as signal processing. Here we present spatio-temporal Fourier analysis of real-time imaging and simulation of laser-induced surface acoustic waves at frequencies up to ∼ 1 GHz in phononic crystal waveguides formed by machining microscopic holes in a silicon slab. In particular we analyse our results as movies in k-space, revealing the effects of diffraction, reflection, waveguiding and attenuation in a particularly simple way.