  We report a development of an electro-optomechanical system based on a
surface acoustic wave (SAW), where a piezoelectric material with a large
optoelastic susceptibility is used for the coupling of both a radio wave and
optical light to the SAW. In the optical domain, we exploit a tensorial nature
of the optoelastic effect to show a polarization dependence of the photon-SAW
interaction. We discuss the construction of two-dimensional SAW focusing
circuits for the coupling enhancement and the optical cavity enhanced
photon-phonon scattering. We estimate an optomechanical coupling rate $g_0$ of
the system and discuss the future direction for the improvement of the coupling
strength.
