Laser

Laser lights

Description

Originally an acronym for light amplification by stimulated emission of radiation. Common usage, however, has applied the term laser to any of several devices that convert a wide range of electromagnetic frequencies into one coherent frequency. This is done by exciting the atoms to reach a higher energy level where their wavelengths are in a single phase. The resultant emission is concentrated into a single directional beam of extremely intense energy. Lasers, first patented in 1960 by Bell Labs, have now been made using ultraviolet, visible, infrared, and microwave wavelength regions. Various types of lasers differ according to characteristics such as output wavelength or wavelengths, output power, duration of emission (i.e., pulsed or continuous), beam divergence and size, coherence, efficiency, and power requirements. It is considered one of the greatest achievements of the 20th century.

Synonyms and Related Terms

laser (Dan., Deut., Fr., It., Ned., Nor., Pol., Port., Sven); láser (Esp.); laser beam

Applications

Communication (optical fibers, satellites), information processing, data storage and scanning
Medicine (surgery, skin treatments)
Spectroscopy (FT-IR, Raman, mass spectrometry)
Photography (holography), printing and graphics, light displays, and entertainment
Geographical mapping in difficult locations (planets, moon, ocean floor)
Materials working (i.e., cutting, welding, drilling) and manufacturing
Military devices (Marking targets, measuring distance
To remove encrustations, overpaint, soot, stains, fungi, and graffiti from several types of surfaces (Asmus 1978 and 2000).

Risks

Can irreparably damage the eyes.
Laser Safety Considerations Abraham 2001

Physical and Chemical Properties

Classifications:

Class 1: Safe for use in most anticipated exposure conditions
Class 2: Visible light laser whose prolonged viewing is dangerous to the human eye
Class 3B: Direct viewing of beam is hazardous, diffusely reflected beam should not be hazardous
Class 4: High power lasers that are hazardous to eyes and skin at all times

Resources and Citations

Meg Abraham, 'Laser Safety Considerations' WAAC Newsletter, Vol.23(1), Jan 2001.link
J.Asmus, "Light Cleaning: Laser Technology for Surface Preparation in the Arts", Technology & Conservation, 3/78, p. 14-18.
J.Asmus, Workshop on Laser Cleaning, AIC meeting, Philadelphia, June 2000.
Encyclopedia Britannica, http://www.britannica.com Comment: "laser" [Accessed 25 Jan. 2006].
Laser Classifications at: http://ptcl.chem.ox.ac.uk/MSDS/laser_classification.html
Wikipedia: Laser (Accessed Sept. 28, 2005 and Oct 2025)
John F Buydos, 'Lasers', Library of Congress Tracer Bullets
Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
Hoechst Celanese Corporation, Dictionary of Fiber & Textile Technology (older version called Man-made Fiber and Textile Dictionary, 1965), Hoechst Celanese Corporation, Charlotte NC, 1990
Van Nostrand's Scientific Encyclopedia, Douglas M. Considine (ed.), Van Nostrand Reinhold, New York, 1976
Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997
The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998