Light diffraction by two spatially separated ultrasonic beams--intermediate region investigations: the case of v< Some formulas are derived, based on the 1OA (1st order approximation method), which describes the intensity distribution of light diffracted by two spatially separated ultrasonic beams. The anlaytical results obtained for the case v << Q are not only in a good agreement with the previous ones, given by Leroy, Blomme, or Kwiek but, what is more important, they are considerably easier to be interpreted physically. The presence of symmetry and asymmetry in diffraction orders (+ 1st and - 1st) is shown. Explanation is given of the rediffraction effect, discovered by Kwiek and Reibold.

Some formulas are derived, based on the 1OA (1st order approximation method), which describes the intensity distribution of light diffracted by two spatially separated ultrasonic beams. The anlaytical results obtained for the case v << Q are not only in a good agreement with the previous ones, given by Leroy, Blomme, or Kwiek but, what is more important, they are considerably easier to be interpreted physically. The presence of symmetry and asymmetry in diffraction orders (+ 1st and - 1st) is shown. Explanation is given of the rediffraction effect, discovered by Kwiek and Reibold.