card
173

laser

OLogy Series
tool
card
173

laser

OLogy Series
tool

What can be used to perform surgery, cut metal, and even listen to your favorite CD? A laser! The term "laser" is actually an acronym for "Light Amplification by Stimulated Emission of Radiation." You can also think of a laser as a special kind of light that's released in a very tight, bright beam. Lasers work by exciting a lot of atoms at one time, emitting the same kind of energy in the same direction.

How a CD Player Works
When you pop a CD into your player, lasers are behind the music. A CD is simply a piece of plastic with tiny bumps arranged along the grooves. As a drive motor spins the disc, a laser "reads" the bumps. An important component of the player is the tracking system, which must be very accurate to keep the laser beam centered on the grooves, gradually moving outward from the center of the disc. The CD player translates the bumps into sound.

The light released by a laser contains one specific wavelength, which means the light is:

very cold

very heavy

one particular color

Are you right?

Correct!

A laser releases light that is one particular color, or monochromatic.

Light -- such as that released by a laser -- is produced when atoms are stimulated, causing the movement of:

electrons

protons

death rays

Are you right?

Correct!

When an atom absorbs energy -- such as heat or electricity -- electrons jump into a higher-energy orbit. When the electrons return to their normal state, the atom releases energy in the form of a photon, or a tiny particle of light.

All lasers are extremely powerful and dangerous.

Fact
or
Fiction
?

Fiction

Some lasers can be very powerful and dangerous, but most of the time, when used properly, lasers are safe and helpful.

Lasers were invented by Albert Einstein.

Fact
or
Fiction
?

Fiction

Einstein did not invent lasers, but his experiments and theories about light led to their development in the 1950s.

laser
What it stands for: Light Amplification by Stimulated Emission of Radiation, or L.A.S.E.R.
Special properties: monochromatic (one color), coherent (photons move in unison), directional (concentrated beam)
Scientists who helped create lasers: Gordon Gould, Charles Townes, and others
Uses: supermarket scanners, surgical devices, CD players, industrial machines

Image credits: courtesy of AMNH.