A planar chart equivalent to Poincaré sphere for expressing state-of-polarization of light

A planar chart for expressing a state of polarization of an arbitrarily polarized light is proposed. The proposed chart is equivalent to the Poincaré sphere, but has an advantage over the Poincaré sphere in that it can be printed on a flat paper. The characteristics of the proposed chart are investigated. The computer-drawn exact chart is shown with important parameter values. Finally, an example of the application of the proposed chart is described.