TE and TM polarization parallel definition

[yefj]

Homework Statement: TE and TM polarization parralel question
Relevant Equations: its a photo

Hello, In the photo on the left bellow E-field is not parralel not to X nor to Z direction.
to what exactly is it parralel?
Thanks.

 

[TSny]

Hello, In the photo on the left bellow E-field is not parralel not to X nor to Z direction.
to what exactly is it parralel?

In the TM wave ("p-polarization"), the electric field is parallel to the plane of incidence and the magnetic field is transverse (perpendicular) to the plane of incidence.