These are nice illustrations but I am looking for a rigorous analysis of the problem. Marcella tried to do this but he wasn't very successful. Or maybe he was successful if we allow his simple state preparation / measurement model. In any case, the critique of Rothman and Boughn shows how classical optics gives a more sophisticated picture.
I just found a paper from 2011 by Beau (http://arxiv.org/abs/1110.2346) which uses the path integral approach and seems promising.