As a result of theoretical analysis an equation is obtained describing the dependence of deflected light intensity on diffraction angle and time. Considerations are carried out for an isotropic, nonmagnetic dielectric medium and Gaussian light beam. The inverse problem is solved, too. Basing on its solution an acousto‐optic method for acoustic pulse parameter analysis is proposed. It allows to reconstruct the acoustic wave envelope basing on the diffraction pattern. This method may be used in investigations of acoustic properties of solids and liquids.