Verification of wedge concentration using a helium neon laser

On the basis of multiple reflections, the concentration of a wedge is given, noting an expression for the concentration ratio as a function of the wedge half angle and the included angle of incidence. Predicted values of approach angles, points of contact, and concentration ratios are compared to experimental data using a helium neon laser as a collimated beam. It is noted that the wedge yields high concentration for small wedge angles and that for a given included angle of incidence, tracking is not required.