PHYS 2212 Module 13.7


Recommended Reading

13.7 Polarization

Learning Objectives

By the end of this section, you will be able to:

  • Explain the change in intensity as polarized light passes through a polarizing filter
  • Calculate the effect of polarization by reflection and Brewster’s angle
  • Describe the effect of polarization by scattering
  • Explain the use of polarizing materials in devices such as LCDs

Polarization of Light

Practice 13.7.1
In what direction is the light polarized after transmitting through the polarizing filter?
Check your answer: A. x
Practice 13.7.2
The following diagrams show the path of light passing through the two polarizers, whose polarizing axes are represented by blue lines. Each diagram also shows the electric field vectors of the light incident on and transmitted by each filter.

Which of these diagrams accurately represents the polarization of the light at each stage?
Check your answer: B
Practice 13.7.3
Three polarizing filters are stacked with the polarizing axes of the second and third filters oriented at 45° and 90°, respectively, relative to the polarizing axis of the first filter. Unpolarized light of intensity I0 is incident on the first filter.

The intensity of light emerging from the third filter is…
Check your answer: E. (1/8)I0


Unpolarized light having intensity I0 strikes a polarizer filter, then passes sequentially through three analyzer filters A1, A2, and A3. These filters are rotated clockwise through the angles shown with respect to the orientation of the polarizer.

What is the intensity I3 of the light transmitted by A3, in terms of the original intensity I0?

Polarization by Reflection