Consider a thin transparent plate surrounded by air. The plate's refractive index is exactly the same as the air's, but it does have a small loss (say of the order of 1%). Let the plate be vertical and normal to our "page" or your computer screen. A laser beam passes through the plate at an acute angle such as 5 degrees, say from the lower right to the upper left. Now is there any mechanism in this system by which some of the light would be scattered towards the upper right? (FWIW, I arrived at this conjecture while following some train of thought that probably wouldn't interest anyone here). If there is such a process, where can I read more about it? Does it have a name? Would the scattered energy form a beam similar in width to the incident one?