Polari rization on of light Ideas for Demonstrations and materials - - PowerPoint PPT Presentation

Polari rization

• n of light

Ideas for Demonstrations and materials needed:

Horizontally and vertically polarized waves:

• slinky and poster board
• available graphics

Showing that light is a polarized wave:

• light source and polarizing plastic sheets

*clear bottle of corn syrup, isn’t necessary, but makes for a colorful display of polarization.

Light waves oscillate in multiple directions.

Head-on view of a light wave. Arrows indicate the direction of oscillation.

For simplicity of description and or calculations, light waves can be thought of as oscillating only in a vertical

• r horizontal direction.

Head-on view of a light wave. Arrows indicate the direction of oscillation.

Demonstration: Polarization of light

Using a white light source, place a sheet of the polarizing plastic in front of the light source and note polarized light intensity. Now place two sheets of polarizing plastic in front of the light source and rotate them in opposite directions to change the angle and amount of polarization.

*For an additional, colorful variation of this demonstration, place a jar of corn syrup, in front of the light source, but between the two polarizing sheets and slowly rotate the jar. Rotating the jar continually changes the degree of polarization of the light entering the jar. The spirally polarized sugar molecules in conjunction with the polarizing sheets makes for a colorful demonstration in light polarization.

The slinky can be used to demonstrate a horizontally or vertically polarized wave. Cylinders of rolled up poster board can be used as either horizontal or vertical polarizers. This is a large scale demonstration that can be interactive for the students. Polarization can be a difficult topic to discuss and for students to

• grasp. Using large scale demonstrations in conjunction with the

smaller scale polarizing sheets can be quite helpful. Also using graphics to represent what happens can be useful.

Here are some graphics that might be useful….