Polarisation

Abstract

In Section 2.1 it was demonstrated that if the free end of a rope is ‘flicked’ in a completely random manner then an unpolarised wave motion will be produced. On the other hand if the free end is ‘flicked’ in the same direction a plane-polarised wave will be formed. Figure 5.1 is one way of representing these two cases. You, the observer, are looking towards the source of the waves. The numbers in Fig. 5.1(a) refer to the order in which the individual plane-polarised waves are generated. It must be emphasised that the process is a completely arbitrary one and that over a long period of time all directions are equally likely. In Fig. 5.1(b), however, the waves always have the same plane of polarisation