Optical absorption of a stack of razor blades: theory and application

We have analyzed the optical absorption properties of the surface of a stack of double-sided razor blades.Our analysis predicts the amount of light absorbed as a function of the angle of light incidence.In addition, we explore the effect of varying cavity wedge angles.All internal reflections are assumed to be specular.Reflection off of blade edges is ignored, as are any cavity resonance conditions.The predictions are compared to detailed measurements using a laser beam. We relate our findings to issues of laser safety, reference blackbodies, and discuss specialty coatings such as Vantablack.