The scattering of Rayleigh surface waves into longitudinal volume waves has been carried out utilizing optical patterns imaged on photoconductive cadmium sulfide films. A 100‐MHz interdigital transducer was used to launch surface waves along the top face of a lithium niobate delay line. Imaging of an optical grating pattern onto a CdS film overlay produces photoconductive variations which interact with the fields associated with the surface wave. The optical pattern, a series of bars, will cause constructive interference of volume waves scattered normal to the surface when the grating periodicity is one wavelength of the surface wave. A theoretical calculation of this scattering efficiency is made and is found to be in excellent agreement with the experimental results. This device offers significant advantages over similar devices in that the scattering grating may be changed or translated quite readily.