Origin of laser
Examples from the Web for laser
Obama is widely believed to tap an ex-physicist who cuts military waste like a laser to become the next secretary of defense.Ashton Carter, the Wonk Who Would Lead the Pentagon|Shane Harris, Tim Mak|December 2, 2014|DAILY BEAST
On his YouTube page, Zavilenski boasts of owning a laser engraver.
“The lair of the laser loves all of you,” he tells a visiting Atlas Obscura tour group.New York’s Hologram King Is Also the City’s Last Pro Holographer|Nina Strochlic|May 27, 2014|DAILY BEAST
If anyone gets a laser rifle, it will be America's commandos.
The Army suggests that laser, microwave or acoustic weapons are the answer.
Casually, without even looking at the Security man, he had somehow centered the laser directly on him.
The laser operator fired and the light beam shot down into the earth, burning a narrow hole.
The water began rising in the walls of the hole, sealed into a shining shaft of fused rock and silicon by the laser beams.
The theory behind the heat projector was simply an extension of the laser theory, plus a few refinements.The Foreign Hand Tie|Gordon Randall Garrett
Therefore, he and his men were in absolute control of the men who controlled the laser.
British Dictionary definitions for laser (1 of 2)
Word Origin for laser
British Dictionary definitions for laser (2 of 2)
Medicine definitions for laser
Science definitions for laser
A Closer Look
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.
Culture definitions for 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.