Diffraction of light by weak ultrasonic fields

Assuming the validity of Raman and Nath's simplified theory for small widths of weak sound fields, an elegant and simple method is presented to derive an expression for the intensity of the first order in the case of weak sound fields. Expressions obtained are found to be identical with those of David, and Bhatia and Noble. Extending this treatment to the case of diffraction by stationary waves it is shown that the intensity of a first order in this case is half that of the corresponding order for progressive waves and this result has also been verified experimentally