# Plane of polarization

#### circuit2000

Joined Jul 6, 2006
33
1)I have a basic doubt on polarization. It is given in book that the plane of polarization is perpendicular to the plane of vibration. What was need for defining the plane of polarization to be perpendicular to the plane of vibration? When I searched the internet, I found a site which says that the plane of polarization is the plane in which the magnetic field vector is oscillating and plane of vibration is the plane in which the electric field vector oscillates. In an electromagnetic wave, the electric field vector is perpendicular to the magnetic field vector. Though this sounds to be true, I would like have the opinion of this forum.

#### recca02

Joined Apr 2, 2007
1,212
its been quite some time since i studied the topic , so it will be wiser to hear what the seniors here say,all i can tell u is if u consider a plot of the fields
with respect to time or space u'll see two sinusoidal waves having one axis common but in perpendicular. did u get the picture?
these fields are always perpendicular mutually

#### DrNick

Joined Dec 13, 2006
110
This is a confusing term. There is polarization as in linear, circular or elliptical polarization for waves in free space. They also use polarization for waves hitting a boundary. There are two types of polarization when it comes to waves hitting a boundary.

1) TE polarization (perpendicular polarization)
In this case the electric field is perpendicular to the "plane of polarization," more commonly known as the plane of incidence. The magnetic field is in the plane of incidence. The plane of incidence is a plane made up of the normal vector to the boundary and the k vector (direction of propagation). This is transverse electric (TE) because the magnetic field has a component that is in the direction of propagation and the electric field is transverse (no component in the direction of propagation).

2) TM polarization (parallel polarization)
In this case the magnetic field is perpendicular to the plane of polarization (plane of incidence) and the electric field is parallel to the plane of incidence (in the plane of incidence).

In both cases the electric and magnetic fields are perpendicular to each other. SO I believe that the answer to your question is:

The plane of polarization (plane of incidence) is made up of the normal to the boundary vector and the k vector (direction of propagation, regardless of the polarization.