Electromagnetic Waves and Polarization

Study Notes

Electromagnetic waves are created by vibrations between an electric field and a magnetic field.
The electric and magnetic fields are at right angles to each other.
Electromagnetic waves are transverse waves.
Electromagnetic waves can be used for various applications such as 3D movies, sunglasses, and cameras.

Only transverse waves can be plane polarized.
All types of electromagnetic waves can be plane polarized.
Plane polarized waves oscillate in a single direction perpendicular to the direction of wave propagation.
Longitudinal waves vibrate along the direction of wave travel, meaning they cannot be polarized.
Sound waves are longitudinal waves and thus cannot be polarized.

The intensity of polarized light passing through a polarizer is dependent on the angle between the direction of polarization and the transmission axis of the polarizer.
The intensity of polarized light after passing through a polarizer can be calculated using Malus's Law: I = I0(cosθ)², where I0 is the initial intensity, I is the final intensity, and θ is the angle between the polarization direction and the transmission axis.
The intensity of polarized light decreases as the angle between the polarization direction and the transmission axis increases.

A polarizer allows light waves to pass through if the direction of oscillation of the electric field matches the alignment of the polarizer.
A polarizer blocks light waves if the alignment of the polarizer is perpendicular to the direction of oscillation of the electric field.
When unpolarized light passes through a polarizer, the intensity of the light is reduced by half.