Hi. So I am studying a bit on acousto-optics and as far as I've gathered, when the Bragg condition is met, the incident ray of light should just be reflected (in a perfect case) with the angle of reflection equal to the angle of incidence. However, this picture does not agree with my thoughts: http://www.mt-berlin.com/pict_0/fig1ao.gif Is it correct? I mean the Bragg diffraction. The picture clearly suggests that the incidence and reflection angles need not be equal..