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laser
9 dictionary results for: Laser
Dictionary.com Unabridged (v 1.1) - Cite This Source - Share This
la·ser 
[ley-zer] Pronunciation Key
[ley-zer] Pronunciation Key –noun Physics.
| a device that produces a nearly parallel, nearly monochromatic, and coherent beam of light by exciting atoms to a higher energy level and causing them to radiate their energy in phase. |
Also called optical maser.
[Origin: 1955–60; l(ightwave) a(mplification by) s(timulated) e(mission of) r(adiation)]
]
Dictionary.com Unabridged (v 1.1)
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2006.
American Heritage Dictionary - Cite This Source - Share This
la·ser
(lā'zər) Pronunciation Key
(click for larger image in new window) n. Any of several devices that emit highly amplified and coherent radiation of one or more discrete frequencies. One of the most common lasers makes use of atoms in a metastable energy state that, as they decay to a lower energy level, stimulate others to decay, resulting in a cascade of emitted radiation. [l(ight) a(mplification by) s(timulated) e(mission of) r(adiation).] |
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The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2006 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Online Etymology Dictionary - Cite This Source - Share This
laser
laser
1960, acronym for "light amplification by stimulated emission of radiation," on pattern of 1955 MASER. A verb, lase, was coined 1962.
Online Etymology Dictionary, © 2001 Douglas Harper
WordNet - Cite This Source - Share This
| laser | |
noun | |
| an acronym for light amplification by stimulated emission of radiation; an optical device that produces an intense monochromatic beam of coherent light |
WordNet® 3.0, © 2006 by Princeton University.
The American Heritage Science Dictionary - Cite This Source - Share This
laser
(lā'zər) Pronunciation Key
(click for larger image in new window)
Short for light amplification by stimulated emission of radiation. A device that creates and amplifies electromagnetic radiation of a specific frequency through the process of stimulated emission. The radiation emitted by a laser consists of a coherent beam of photons, all in phase and having the same polarization. Lasers have many uses, such as cutting hard or delicate substances, reading data from compact disks and other storage devices, and establishing straight lines in geographical surveying.
Our Living Language : A laser emits a thin, intense beam of nearly monochromatic visible or infrared light that can travel long distances without diffusing. Most light beams consist of many waves traveling in roughly the same direction, but the phases and polarizations of each individual wave (or photon) are randomly distributed. In laser light, the waves are all precisely in step, or in phase, with each other, and have the same polarization. Such light is called coherent. All of the photons that make up a laser beam are in the same quantum state. Lasers produce coherent light through a process called stimulated emission. The laser contains a chamber in which atoms of a medium such as a synthetic ruby rod or a gas are excited, bringing their electrons into higher orbits with higher energy states. When one of these electrons jumps down to a lower energy state (which can happen spontaneously), it gives off its extra energy as a photon with a specific frequency. But this photon, upon encountering another atom with an excited electron, will stimulate that electron to jump down as well, emitting another photon with the same frequency as the first and in phase with it. This effect cascades through the chamber, constantly stimulating other atoms to emit yet more coherent photons. Mirrors at both ends of the chamber cause the light to bounce back and forth in the chamber, sweeping across the entire medium. If a sufficient number of atoms in the medium are maintained by some external energy source in the higher energy state—a condition called population inversion—then emission is continuously stimulated, and a stream of coherent photons develops. One of the mirrors is partially transparent, allowing the laser beam to exit from that end of the chamber. Lasers have many industrial, military, and scientific uses, including welding, target detection, microscopic photography, fiber optics, surgery, and optical instrumentation for surveying. |
The American Heritage® Science Dictionary
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2002 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
American Heritage New Dictionary of Cultural Literacy, Third Edition - Cite This Source - Share This
laser
laser
A device that produces a very narrow, highly concentrated beam of light. Lasers have a variety of uses in such areas as surgery, welding and metal cutting, and sound and video recording and reproduction. The name is an acronym for light amplification by stimulated emission of radiation.
The American Heritage® New Dictionary of Cultural Literacy, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
American Heritage Stedman's Medical Dictionary - Cite This Source - Share This
laser la·ser (lā'zər)
n.
Any of several devices that convert incident electromagnetic radiation of mixed frequencies to discrete frequencies of highly amplified and coherent ultraviolet, visible, or infrared radiation; used in surgery to cut and dissolve tissue.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Free On-line Dictionary of Computing - Cite This Source - Share This
laser hardware
(Light Amplification by Stimulated Emission of Radiation) The type of light source used in a laser printer.
(2003-05-08)
The Free On-line Dictionary of Computing, © 1993-2007 Denis Howe
American Heritage Abbreviations Dictionary 3rd Edition - Cite This Source - Share This
| laser light amplification by stimulated emission of radiation |
The American Heritage® Abbreviations Dictionary, Third Edition
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
Copyright © 2005 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.
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