title: Rings observed on a transparent plate coated with a diffusing layer.
abstract: We have observed a series of regularly spaced concentric rings on a transparent plate with parallel faces coated with a thin layer of diffusing material on which a beam of light was focused. This is not due to the phenomenon of interference or diffraction but is caused simply by a visualization on the diffusing layer of the light intensity resulting from multiple total or partial reflections on the two faces. We obtained good agreement between experimental measurements and a mathematical model. We followed two approaches in the calculations: one using a closed expression, and the other a simulation by the Monte Carlo method. Both methods are based on Fresnel's formula for the transmission of light.
authors.forename: M
authors.initials: M
authors.lastname: Bourdinaud
authors.forename: H
authors.initials: H
authors.lastname: Blumenfeld