Light & Optics: Polarization

Determine the relationship between the intensity of light transmitted through a polarizer and the angle of polarization.

Motion Sensors

Your students can easily combine hand-collected data with measurements from a light sensor to illustrate their relationship. Enlarge graph.

Lab Summary:

Students will use a Light Sensor to investigate polarized light. Students will measure the light intensity as light passes through polarized material. They will examine the shape of the graph and determine how light intensity is related to the angle of polarization.

As an extension, the students can examine the graph of light intensity versus cosine squared of the angle to verify Malus Law. This law states the intensity of light varies linearly as the cosine squared of the angle between the polarizing directions of two polarizer.

Download free labs:

(student versions)

Computer-based lab (PDF, 512 KB)

Xplorer GLX-based lab (PDF, 1,1 MB)

Method:

Use a Light Sensor to measure the light intensity from a small light source when the light travels through a single polarizer and when it travels through two polarizers. Change the angle of one polarizer relative to the other and compare the light intensity.

Here's What You Need:

Required for computer-based lab:

(See lab download for Xplorer GLX-based lab requirements, which may differ)

Probeware

Other Materials

Lab Manual:

The computer-based activity is included in Explorations in Physics (PS-2810). The Xplorer GLX-based lab is included in Physics with the Xplorer GLX (PS-2826). Both manuals are complete with Teacher Information pages, student instructions and handouts, and sample data.

For your convenience, we offer bundles which provide the probeware for the activities in the manual. For more, please see:
Computer-based Physics Lab Manual and Bundles
Xplorer GLX-based Physics Lab Manual and Bundles