Аннотация:We report the results of the analysis of the elastic field structure in the region near the Y-plane of the BaTiO3 crystal. THe assumption of given interference light pattern with a fringe spacing (Lambda) and an independent on y modulation index m at steady-state is used. The photorefractive grating vector kg is assumed to be parallel to Z-axis of the crystal. Taking the crystal surface to be traction free we consider tow cases: (a) dielectric boundary and (b) short-circuited boundary.