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why the laser beam iss red?
- ahmed (age 12)
Ahmed-If you've ever looked at light through a prism, or just looked up
at a rainbow, you know that most light is made up of a number of
different colors. An ordinary light bulb looks white, but it's really
made up of all the different colors of the rainbow. If you want to, you
can make different colored lights by putting a filter over a regular
light bulb that only lets certain colors through, but the light bulb is
still making all the colors. It's just that you only see certain
ones.The way a laser works different from this, though. Unlike an
ordinary bulb, which creates all the different colors, a laser is
designed in such a way that it produces only a single wavelength, or
color, of light. It also makes the light perfectly focused into a beam.
Physicists say the light is "coherent."By the way, not all lasers are
red. They make lasers in other colors, too, depending on the type of
gas inside. The helium-neon laser, which produces the red light you are
familiar with, is the most common one, though.MG
(republished on 07/28/06)
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