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Hasegawa, Harry Lawndale Community Academy
1) Students will learn basic facts of polarization
2) Demonstrate some phenomenological activities illustrating
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
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
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.