EN
Calculations of acousto-optic diffraction spectrum are fulfilled on the basis of modified Raman-Nath equations which take into consideration the acoustic energy walk-off. It is shown that, depending on acousto-optic interaction geometry, the walk-off can change essentially angular and frequency ranges of the interaction. Coefficients of broadening are put in practice as characteristics of the walk-off influence. The calculations are carried out for 5° crystal cut of a paratellurite crystal in wide ranges of ultrasound frequencies and Bragg angles.