Superimposition
Any form of polarisation can be represented as a superimposition of two basic types of polarisation The most often used as a base, are
1. Two linear polarised waves, the polarisation directions of which are perpendicular to each other This results in
Arbitrary directional linear polarisations with an insignificant phase difference and variable intensities
Circular polarisation with a phase difference of N4 and equal intensities
Elliptic polarisation in all other cases
2. One clockwise and one counter-clockwise circular polarised wave. This results in Arbitrary directional linear polarisations with equal intensities and a variable phase difference Circular polarisation when one of the basic amplitudes is removed Elliptic polarisation in all other cases