1. Polarization

2. How it works

3. Polarizer
Starting with un-polarized light, the first polarizer cuts intensity in half. S = So/2
If light is already polarized or has come through a polarizer use: S = So Cos2(θ)

4. Example: What is the final intensity after passing through two polarizers that are perpendicular?
So = 1200 W/m2

5. Example: What is the final intensity if a third polarizer is added in the middle oriented at 45o?
So = 1200 W/m2

6. Example: What is the final intensity if a third polarizer is added in the middle oriented at 55o to the first polarizer?
So = 1200 W/m2

7. Sunglasses