Page 333 - Microsoft Word - LessonPlan-Overview.doc

Unit 9: Light Page 28

should block the light completely in Did you know that the word LASER

one configuration and allow it to stands for Light Amplification by
pass-through the other way. Stimulated Emission of Radiation?
And that a MASER is a laser beam
with wavelengths in the microwave

part of the spectrum? Most lasers
Why does this happen? Polarization
fire a monochromatic (one color)
is a way of filtering light. Try this:
narrow, focused beam of light, but
in a shallow pan filled with water,
more complex lasers emit a broad
make a few waves and notice how
range of wavelengths at the same
they travel from one side of the
time.
pan to the other. Now add a plastic
comb, and notice how the waves In 1917, Einstein figured out the
stop when they hit the comb – not basic principles for the LASER and
many pass through to the other MASER by building on Max Planck’s
side (watch out for the waves that work on light. It wasn’t until 1960,
creep around the edges – we’re though when the first laser actually
focusing on the pass-through emitted light at Hughes Research
waves only). The comb are the Lab. Today, there are several
sunglasses, and the water waves different kinds of lasers, including

are the light waves. gas lasers, chemical lasers,
semiconductor lasers, and solid
Add a second comb at 90 degrees
state lasers. One of the most
from the first (as you did with the
powerful lasers ever conceived are
sunglasses) so it resembles a mesh
gamma ray lasers (which can
screen, and notice now how NONE
replace hundreds of lasers with
of the waves make it through the
only one) and the space-based x-
comb array. Polarization can filter
ray lasers (which use the energy
out various amounts of light,
from a nuclear explosion) – neither
depending on the angle the combs
of these have been built yet!
make with each other (90 degrees
apart equals total block-out).

7. Light Bulbs: In the dark, aim
your laser at a frosted
incandescent light bulb. The bulb

will glow and have several internal
reflections! What other types of
light bulbs work well?

© 2010 Supercharged Science www.ScienceLearningSpace.com

333