The following animation presents the superposition of two waves that have the same amplitude and wavelength, are polarized in two perpendicular planes and oscillate in the same phase. Oscillating in the same phase means that the two waves reach their peaks and cross the zero line in the same moments. The superposing components are visualized with red and green color, respectively. The wave resulting from the superposition is shown in light blue.
When the intersecting plane is looked at from the front then the following image is seen:
(Attention! The two animations are not synchronized!)
As you can see, the result of the superposition is another wave that is plane-polarized and its plane of polarization forms a 45° angle with the polarization planes of the component waves.