The acousto-optical crystals are frequently used, indispensable elements of high technology and modern science, and yet their precise numerical description has not been available. In this paper an accurate, rapid and quite general model of the AO interaction in a Bragg-cell is presented. The suitability of the simulation is intended to be verified experimentally, for which we wanted to apply the most convincing measurement methods. The difficulty of the verification is that the measurement contains unknown parameters. Therefore we performed an elaborated series of measurements and developed a method for the estimation of the unknown parameters.