PE-0200 Polarisation of Light

In the year 1809, Etienne Malus discovered the polarization of light by reflection and stated a law which describes the intensity distribution of polarized light as a function of the relative orientation of a polarization analyser. At that time his findings were in contradiction to the presumption of light waves being longitudinal rather than transversal. His discovery had far reaching consequences for the wave theory of light, and his unambiguous experimental results launched a big debate, among the leading scientists about the wave properties of light. Finally, as a compromise light was conceded to have transversal as well as longitudinal character. Two years later Dominique Arago investigated a sample of quartz and discovered its optical activity, a property of many natural and also synthetic materials. Later on, Augustine Fresnel could explain the effect of optical active materials on light by introducing the phenomenon of circular birefringence. In this series of experiments the polarization state of the light sources in use is determined. Furthermore, polarized light is used to prove the Malus’ and Fresnel’s Laws with respect to their states on polarization. The influence of crystal wave plates and optically active materials on polarization is studied.