Acoustic surface wave Δ v/v waveguides on anisotropic substrates

Accurate measurements of the phase and group velocity dispersion curves have been made for Δv/v waveguides on (001) 〈 110 〉 Bi12GeO20. The measurements are shown to be in good agreement with the results of a simple theory which includes the effect of substrate anisotropy. Results indicate that the acoustic energy is bound more tightly to waveguides fabricated on crystal orientations where anisotropy provides a reduced diffraction loss for unguided waves.