Malus law – interferometric interpretation

The aim of the present work is the description of a novel interferometric approach to the commonly known Malus law. In this approach we have described an analyzer as an element realizing the interference of two waves being the components of the linearly polarized wave emerging from the polarizer. We have proposed a decomposition of the polarization state of the light incident on the analyzer into two different bases. The choice of a first base – linearly polarized – allows interpreting Malus law as an interference of two linearly polarized waves with the same polarization state, different amplitudes and the same phases. The second decomposition, based on circularly polarized vectors, leads to the description in which Malus law can be interpreted as an interference of two waves with the same amplitudes but different phases. This allows the introduction of the concept of the geometric phase into Malus law as well as the visualization of this phase on the Poincaré sphere.