1. Light is not just a wave, it’s transverse wave!
Polarization of Light
Light is not just a wave, it’s transverse wave!

2. What is Polarization?
Strictly defined, polarization is the phenomenon in which transverse waves are restricted in their direction of vibration. Light can either be plane- polarized, circularly polarized, or elliptically polarized

3. Isn’t light always plane-polarized?
A very common misconception is that light, or radiation in general, is naturally plane-polarized. However, unpolarized light actually vibrates equally in all directions perpendicular to its direction of propagation. In order for it to become polarized, the wave itself has to be perturbed somehow.
How do you think a wave may be perturbed in such a way to become polarized?

4. Types of Polarizers
There are 4 common ways a wave can become polarized:
Double Refraction
Reflection
Scattering
Polarizing filter
All 4 ways can be achieved either
naturally or artificially.

5. Types of Polarizers Cont’d
Double Refraction:
Waves can become plane-polarized when passing through a material when that material causes the different planes of polarization in a wave to travel at different speeds.
Reflection:
Waves can also become
polarized when they reflect
of a non-metallic surface.

6. Types of Polarizers Cont’d
Scattering:
Light can also become polarized when it passes through a gas.
Polarizing filters:
Polarizing filters are materials that, either naturally or artificially, polarize incoming light waves.

7. Final notes…
Plane-polarizations and circular- polarizations by far occur the most often. Some rotate plane-polarized waves through an angle, or perturb it in such a way that it becomes circularly polarized. This is a result of medium optical activity.
So, lets see what how well we understand polarization by considering an applet of a series of Polaroid filters