Introduction of lasers:
"Laser light" redirects here. For the song, see LaserLight. For laser light show, see laser lighting display. For other uses, see Laser (disambiguation).
United States Air Force laser experiment
Red (660 & 635 nm), green (532 & 520 nm) and blue-violet (445 & 405 nm) lasers
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The term "laser" originated as an acronym for "light amplification by stimulated emission of radiation".[1][2] The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light coherently. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers. Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum, i.e., they can emit a single color of light. Temporal coherence can be used to produce pulses of light as short as a femtosecond.
Among their many applications, lasers are used in optical disk drives, laser printers, and barcode scanners; DNA sequencing instruments, fiber-optic and free-space optical communication; laser surgery and skin treatments; cutting and welding materials; military and law enforcement devices for marking targets and measuring range and speed; and laser lighting displays in entertainment.
Contents [hide]
1 Fundamentals
1.1 Terminology
2 Design
3 Laser physics
3.1 Stimulated emission
3.2 Gain medium and cavity
3.3 The light emitted
3.4 Quantum vs. classical emission processes
4 Continuous and pulsed modes of operation
4.1 Continuous wave operation
4.2 Pulsed operation
4.2.1 Q-switching
4.2.2 Mode-locking
4.2.3 Pulsed pumping
5 History
5.1 Foundations
5.2 Maser
5.3 Laser
5.4 Recent innovations
6 Types and operating principles
6.1 Gas lasers
6.1.1 Chemical lasers
6.1.2 Excimer lasers
6.2 Solid-state lasers
6.3 Fiber lasers
The word laser was coined as an acronym for Light Amplification by the Stimulated Emission of Radiation. The special nature of laser light has made laser technology a vital tool in nearly every aspect of everyday life including communications, entertainment,
manufacturing, and medicine.
Introduction to lasers
as we all know laser technology was developing day to day we must know the advantages and disadvantages of them and know the common useful developments of laser
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8 сен 2024