Light & Optics: Polarization
Determine the relationship between the intensity of light transmitted through a polarizer and the angle of polarization.
Your students can easily combine hand-collected data with measurements from a light sensor to illustrate their relationship.
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.
Theory
The light that eminates from most sources is unpolarized, which is to say that the electromagnetic waves are oriented in all axes. Light can become polarized, often through reflection from a surface or by passing through a filter that only allows waves of a certain orientation to pass through. Rotating a polarizing filter while using a Light Sensor will demonstrate this phenomena.
Downloads
- Computer-based lab (PDF, 512 KB) (511 KB, .pdf)
(student version)
- Xplorer GLX-based lab (PDF, 1,1 MB) (1.14 MB, .pdf)
(student version)
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
U.S. Educator prices shown.
Required for computer-based lab: (See lab download for Xplorer GLX-based lab requirements, which may differ)
Probeware
PASPORT Light Sensor (PS-2106A) - $65
Features a wide measurable range by offering three light ranges accommodating various different measurement situations. For use with PASPORT Interfaces.
Xplorer GLX (PS-2002) - $349
The Xplorer GLX is a data collection, graphing, and analysis tool designed for science students and educators.
Other Products
Basic Optics System (OS-8515C) - $498
A group of components designed to allow students conduct various optical experiments.
Aperture Bracket (OS-8534A) - $89
With the Aperture Bracket, a student can vary the spatial resolution of the Light Sensor in six steps from 0.1 to 1.5 mm. Mounts to Basic Optics Bench.
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
