Laser

LASER: acronym for Light Amplification by Stimulated Emission of Radiation. It is a device that produces a very narrow, powerful beam of light. Some beams are thin enough to drill 200 holes on a spot as tiny as the head of a pin. The ability to focus laser light so precisely makes it extremely powerful.  For example, some beams can pierce a diamond, the hardest natural substance.  Others can trigger a small nuclear reaction.  A laser beam also can be transmitted over long distances with no loss of power and is therefore very useful for communication purposes.  Some beams have reached the moon. The special qualities of laser light make it ideal for a variety of applications.  Some types of lasers, for example, are used to play music, read price codes, cut and weld metal, and transmit information.  Lasers can also guide a missile to a target, repair damaged eyes, and produce spectacular displays of light.  Still other lasers are used to align walls and ceilings in a building or to print documents.  Some lasers even can detect the slightest movement of a continent.   

How Lasers are used  

Lasers can do a number of incredible things.  Their special qualities make them particularly useful in recording, storing, and transmitting many kinds of information. The most common uses of lasers include the recording of music, motion pictures, computer data, and other material on special discs.  Bursts of laser light record such material on the discs in patterns of tiny pits.  The discs with recorded music and computer data are called compact discs (CDs). A laser beam's tight focus allows much more information to be stored on a CD than on a phonograph record, making CD's good for holding data as well as music.  Some CD's even can hold an entire encyclopedia.  A disc used for storing data is usually called a CD-ROM (Compact Disc Read-Only Memory).  Such discs store databases (large files of information held in computers) and are used widely by businesses, libraries, and government agencies.    

Lasers can also read and play back the information recorded on discs.  In a CD player, a laser beam reflects off the pattern of pits as the compact disc spins.  Other devices in the player change the reflections into electrical signals and decode them as music.  More lasers are used in CD players than in any other product.    

Lasers are used to record movies on large platters called videodiscs.  In addition, laser beams can produce three-dimensional images in a photographic process called holography.  

Another great use of the laser is in the field of fiber-optics communication (see fibre-optics for more information).  

Previous Menu: Future                                                                                                                  Next Topic: Fibre Optics