The ‘non-refractive effect’ in translucent diffusers: A geometrical model

Abstract

When coherent light impinges on a rough diffuser with an angle of incidence different from zero, the maximum of the mean scattered intensity moves away from the direction that would be given by the Snell law if the interface were flat. This phenomenon is known as non-refractive effect. We report here that we have found experimentally that the same effect occurs for white light and that a simple geometrical model accounts for it.