Electromagnetism and polarization

[Enola Straight]

Light is made of a magnetic field and an electric field, each of which is at right angles to the other as well as the light beam itself.

Polarization is also at right angles to the beam of light.

1. Is the angle of Polarization carried by the electric or magnetic field?
2. Is that a function of the field or merely a coincidence?

[Kuroneko]

Light is made of a magnetic field and an electric field, each of which is at right angles to the other as well as the light beam itself.

Polarization is also at right angles to the beam of light.

Ah. On a piece of paper, draw two coordinate axes orthogonal to each other. Let's say the electric field oscillates along the x-axis and the magnetic field along the y-axis, with the direction of wave propagation either into or out of the page, in the third dimension (z-axis, which we'll leave to the imagination). They are mutually perpendicular. Now, draw the lines y = x and y = -x, and realize that those two lines and the z-axis are also mutually pependicular. This represents a wave with different direction of polarization, and this wave is different that the first even if it has the same phase and frequency in addiction to the same direction of propagation. Speaking of phase, the phase difference between the electric and magnetic fields what polarization actually is; what you are referring to is more properly called polarization direction.

1. Is the angle of Polarization carried by the electric or magnetic field?

Either or both. 'Either' because given a direction of wave propagation, the the direction of oscillation of the electric field determines both the polarization direction and the direction of oscillation of the magnetic field, and likewise for the magnetic field. 'Both' because they are not really separable in any physically meaningful sense.

2. Is that a function of the field or merely a coincidence?

It is a function of the field. The key thing to realize is that the electromagnetic field is a vector field, rather than a scalar one.

[Il Saggiatore]

Light is made of a magnetic field and an electric field, each of which is at right angles to the other as well as the light beam itself.

This works for electromagnetic waves in vacuum.
In materials it is a bit more complicated.

Polarization is also at right angles to the beam of light.

An electromagnetic wave is said to be polarized if the electric field (described by a vector) oscillates in a well defined plane ("plane polarized"), or if this plane rotates around the direction of propagation with a constant angular speed ("circular polarized").

1. Is the angle of Polarization carried by the electric or magnetic field?

Usually the polarization is defined with the electric field.
Since the magnetic field has a fixed angle with respect to the electric field, one can define the polarization with the magnetic field as well.
Whether an EM wave is polarized, does not depend on using the electric component or the magnetic component to define the polarization.

2. Is that a function of the field or merely a coincidence?

Polarization is defined in terms of the fields.