S vs P polarization

[geo_alchemist]

Let us imagine a surface, with X and Y axes on it and Z axis normal to it.
well, the theory, (in my particular case, some article) says that S polarized light, propagating along the x-directioin possesses only electric field components, Ei, paralel to the surface (||y-direction), i.e. transversal electric waves have Ei=(0, Ey, 0), while P-polarized light has Ei=(Ex, 0, Ez).

The question:

I understand that S-polarized light, propagating along x-direction has only electric field components, Ei, paralel to the surface. Ei=(0, Ey, 0), since in case of s-polarization E is perpendicular to plane of incidence.

Also I understand that P-polarized light, propagating in the same x-direction has Ez component, since in case of P-polarization E is in the plane of incidence.


what I do not understand is, why p-polarized light has Ex component.

[Andy Resnick]

A picture is worth 1000 words:

http://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/tayu/ACT05E/img/05IMG/05_11.jpg

Does this help? Otherwise, please refer to the diagram and tell me which directions you are calling x,y, and z.

[geo_alchemist]

It seems that I understand bt it still is a bit foggy for me. Any further clarification would be greatfully appreciated.
Here is modified image with x, y and z.
http://img232.imageshack.us/img232/2802/0511copy.jpg (http://img232.imageshack.us/i/0511copy.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

[Andy Resnick]

Do you see the essential difference between s- and p- polarization? It's not the (x,y,z) components per se, it's whether or not the electric field is in the plane of incidence.

[geo_alchemist]

Essential difference I see perfectly. what I need is to describe this difference in terms of Ex, Ey and Ez.

Anyway, now I understand it, thanks for picture ;)