Polarization
Hasegawa, Harry Lawndale Community Academy
762-7745
Objectives
1) Students will learn basic facts of polarization
2) Demonstrate some phenomenological activities illustrating
interference patterns.
3) Make "take-home" project of the interference pattern.
Equipment and Materials
Microprojector Clear plastic box
Crystals of: Polarizing films
sugar Cellophane tape
epsom salt Microscope slides
salol
mica
salt
Recommended Strategies
Review light waves and experiment with polarizing film.
Demonstrate the nature of polarized light showing that polarized light
travels in a single plane instead of the 360 degree of unpolarized
light.
Demonstrate the interference pattern of various crystals which are
placed between two polarized films on the microprojector.
When light passes through a polarized film, the many color rays
(or wave lengths) which make up the white light travel at various
velocities and break up or interfere with another ray .
A wave length or white light is then subtracted and shows the
complementary color-- the color that is left when white light
is subtracted. This is the interference pattern.
Demonstrate light reflecting from a smooth surface such as plastic
is polarized. The reflecting light comes to the eye in a single plane.
Show that many digital read-outs are also polarized.
Have students make a take-home project demonstrating interference
patterns by placing a number of small pieces of cellophane tapes
randomly on a microscope slide. Then view the slide placed between
two polarizing films.
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