1. Electromagnetic waves and polarization

2. Electromagnetic waves are made up of both a magnetic field compoonent (M) shown horizontally in this diagram and an electric field component (E) shown vertically
By convention we refer to the electric field component of the wave when we talk about the orientation of the wave.

3. 1

4. 1
Sin θ θ

5. Sin θ θ
This is why the term 2π is used in wave equations.
The phase of any part of the wave is therefore a fraction of 2 π

6. π/2
Sin θ π 2π θ
2π/3

7. Transverse Waves And Polarization

8. Polarization.
Polarization is a phenomenon associated with Transverse waves and not longitudinal waves.
If all the vibrations of a transverse wave are in a single plane, the wave is said to be plane-polarized.
plane-polarized wave

9. Polarized waves heading off in the same direction
Unpolarized waves heading off in the same direction

10. Applies only to transverse waves
A vertically orientated transverse wave can pass through the slot below but a horizontal wave cannot.
Transmitted wave
Reflected wave
Applies only to transverse waves

11. Steel grid
klystron
Microwaves exhibit polarization.

13. Polarisation of waves from a transmitter
The revveiving elements on these antenae are horizontal because the radio waves from the transmitter are polarised horizontally.

14. A polaroid filter lets only the correctly polarised light through

15. What happens with two polarizing filters?

16. Producing polarised lightl