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Lasers
The word laser is an acronym. It means Light Amplification by
Stimulated Emission of Radiation. A laser is basically just light that is
focused into a very narrow beam. There are 5 common types of lasers. They are:
Solid-State Lasers.
Solid-state lasers are the most powerful form of lasers. There are three types
of solid-state lasers. The first type uses
rods of ruby crystals with the ends coated with a highly
reflecting nonmetallic film. The other two types of solid-state lasers are
neodymium-doped glasses and regular crystals.
Gas Lasers.
Gas lasers are cylinders that have pure gas, mixed gases, or metal vapors in
them. Then the cylinders are pumped by ultraviolet light, electron beams,
electric current, or chemical reactions. Some common types of gas lasers are
helium-neon laser and the carbon dioxide laser.
Liquid Lasers.
Liquid lasers are very similar to gas lasers in the sense that they use a glass
cylinder. But instead of gas they are filled with liquid. Liquid lasers can also
be tunable meaning that dome of them have a prism in the cylinder that can be
rotated to produce a different color.
Semiconductor
Lasers.
Semiconductor lasers are the smallest lasers. A semiconductor laser is basically
a junction between two flat layers of gallium arsenide. Semiconductor lasers are
so small that a million of them could fit on your fingernail. These lasers are
called quantum-dot vertical-cavity surface-emitting lasers. These lasers are
used for CD players, laser printers, computers, etc. These lasers are also used
for fiber-optic communication systems.
Free Electron
Lasers.
Free electron lasers use an array of magnets to excite free electrons. This kind
of laser was first developed in 1977 and is now used in important research
equipment. They are tunable over a larger range than dye lasers. They become
more difficult to use at higher powers but usually work properly from infrared
through ultraviolet wavelengths. Theoretically they should work up to the X-ray
wavelength. Eventually through lots of research free electron lasers should be
able to produce very high-power radiation that is too expensive to produce now.
Uses.
Lasers can be used for just about anything. Lasers are currently being used in
scientific research, communications, medicine, the military, and the arts.
Powerful laser
beams can be focused to generate enormous temperatures. That is used for
drilling holes in diamonds, shaping machine tools, trimming microelectronics, to
cut fashion patters, synthesize a new material, and also to attempt to induce
controlled nuclear fusion. Those are just a few uses for lasers, but there are
many more.
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