This paper presents the principle of a new method of laser beamsteering using the photo-refractive effect. This method uses variable, thick diffraction gratings recorded in a photorefractive medium to deflect a laser beam. Two geometrical configurations for writing .he thick gratings, and the relative merits of each are discussed using k-space diagrams. Two methods of controlling the writing beams to vary the recorded grating are also discussed. The results of a proof of concept experiment using bismuth silicon oxide crystals are reported.