Word: lasered
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
From repairing damaged retinas in the human eye to burning precision holes in industrial diamonds, the list of uses for laser light has grown steadily since the fierce, pure beams were first projected less than ten years ago. A recent application may yet prove to be one of the most practical of all. With lasers (for "light amplification by stimulated emission of radiation") to help them take their pictures, Professor George Stroke and his associates at the University of Michigan are perfecting the techniques of holography-three-dimensional photography without the use of a lens...
Disciplined Waves. The basic principles of holography were worked out 20 years ago by British Physicist Dennis Gabor, but they could not be put to use effectively without the peculiar light that lasers now provide. Unlike "white" light from the sun or an electric light bulb, which radiates in all directions and consists of a whole spectrum of colors, light waves from a laser are highly disciplined or "coherent." They are of only one color-which means that they are all of the same frequency. And they all emerge from the laser in step-in phase with each other...
...produce a hologram, light from a laser is split into two beams, one of which is directed by a mirror onto a sheet of photographic film. The other beam is used to illuminate the subject. When the laser light hits the subject, it is scattered by the irregular surface and reflected back toward the film. As a result, many of the reflected light waves are jumbled and out of phase both with each other and with the light from the undisturbed beam reflected by the mirror. When the light waves from subject and mirror are reunited at the surface...
Holography Handicaps. To pluck a hologram and release its light waves, a laser beam is passed through it. As the laser beam hits the hologram's interference pattern, it is diffracted into light waves that duplicate those that were reflected from the subject. The viewer sees the subject of the picture in three dimensions, apparently suspended behind the hologram at the same distance it was from the sheet of film...
...computer. In an experiment for the Defense Department, they tracked the payload of a Minuteman missile, took infra-red measurements of the plasma sheath of ionized air that was created when it plunged back into the atmosphere below them. Another experiment, communication with earth through a laser beam, was only partially successful. After several fruitless attempts, the astronauts spotted the blue-green beam from a laser-transmitting station in Hawaii, aimed their own beam toward it, but were unable to keep it in sight long enough for voice communications...