Perturbation analysis of acoustic wave scattering at rough solid-solid interfaces

We apply a boundary perturbation approach to model the scattering of acoustic waves at rough solid-solid interfaces. This method incorporates mode conversion and allows straightforward separation of specular and diffuse components, the relative fractions of which play an important role in determining thermal boundary resistance and the performance of acoustic phonon devices. The effect of acoustic impedance mismatch on the distribution of scattered waves is investigated, as well as the coupling to interface modes.