Magic beam still showing its versatility

Press, Volume CXIII, Issue 33141, 3 February 1973, Page 11

Magic beam still showing its versatility

(From

KERRY MYERS,

in Neu> York)

An early description of the laser - beam labelled the phenomenon the “light fantastic”—a fanciful tag but a description which is proving only too true today. The uses of the laser beam have spanned such diversified fields as warfare, dentistry, space exploration, surgery and communications. And the question in the minds of, many researchers is “just what can the laser do next?” Ft was on an afternoon in July, 1960, when a physicist, Dr Theodore Maiman achieved the first operating laser in a laboratory near Malibu Beach. The scientist, then 33, later described the dicovery as a “thrilling moment.” For many years after the invention of the tool, the laser created an image out of the pages of science fiction. The “death-ray” image was enhanced when the military applications were mentioned. Laser-guided bombs, munitions delivery and gunfire have been commonly used in the war in Vietnam. And rumours about "deathravs,” “gun vaporisers,” and “electro-optical” warfare are common. H-bomb At the Kirtland United State Air Force base in New Mexico all three armed s >rvices are supposedly hard at work on secret laser warfare programmes. French scientists, using what is considered the world’s most powerful laser, have generated a succession of tiny thermonuclear explosions. The development, in 1969, was regarded as an important step towards taming the energy of the hydrogen bomb. The full potential of laser beams in the communications field has yet not been realised according to laser researchers. It is possible, without cables, tubes or phone wires to transmit the total television and radio programming of a major city to a point miles away using one concentrated pulse of light. Demonstrations of the laser’s communications advantages are seen as the beginning of an eventual network of beams connecting city to city, state to state and, by using satellites, nattion to nation. After inventing the laser, Maiman left Hughes Aircraft

and became director of a laser manufacturing company which he later sold to Union Carbide. He now heads a new company and is in the process of manufacturing a laserpowered television set which will need no picture tube. The set, three by four feet, is only a few inches thick and hangs on the wall like a picture. Still inefficient “What I envisage in the near future,” he said, “is the use and improvement of lasers in scientific instrumentation, television systems, short range communications, computers, and of course, medicine. “The laser, however, is still a highly inefficient device. “Less than 1 per cent of the energy it generates comes out as usable light; the rest of it comes out as heat and has to be stored somewhere and cooled off.” In the field of dentistry and medicine the laser has proven a unique boon to treating damaged tissue. Lasers have the ability to seal passages which cause tooth decay and to fuse enamel to prevent original cavities. Since 1969 several thousand Southern Californians have been treated by beam therapy for many optical ailments, including retina damage. Aiding blind Physicians have already used laser knives to perform bloodless spleen and liver surgery on experimental animals. From the operating table, the laser has also been used successfully in earthmoving constructions. No matter what type of tunnelling machine is used the laser shines on a target near the boring supervisor and he watches the target to make corrections as needed. They can also be set up in pipelines under construction to prove similar guides. The laser can cast a direct beam up to 2000 ft without any spreading of the beam on the target. Super-lasers can be tele-scope-focused to cast a ray with a spread of only onethird of an inch per mile from the source. One manufacturer uses lasers to punch precise holes in the rubber nipples of baby bottles —an apparel firm uses one to cut cloth to patterns. A laser-equipped cane for the blind sends out invisible light to detect obstructions at eye and waist level.

Dr Arthur Shawlow, Stanford University, a laser pioneer, believes that his laser will be used one day for scores of everyday tasks—-

from lighting the gas range to arming ourselves against burglars to peeling potatoes —who knows where the possibilities end.