Word: fibered
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...optical wires a reality. One development was the invention in 1960 of the laser, a device capable of generating an intense narrow beam of light that, for all practical purposes, did not diverge. Miniaturized lasers make it possible to couple powerful light beams accurately with hair-fine glass fibers. Another was the perfection, by Corning Glass Works, of a fiber of glass so pure that it could transmit light long distances. The third accomplishment was the devising, by engineers at Bell Labs and elsewhere, of methods of integrating fiber optics into modern telephone systems...
...waves. In a typical optical arrangement (see diagram), sound waves entering a telephone microphone are converted into electrical signals. These signals pass through an encoder, which converts them into electrical pulses that switch a laser on and off, interrupting a light beam being sent into the end of a fiber. The light thus travels in a series of pulses, not unlike Morse code, that race along the glass "wire." At the end of their journey, these light pulses are picked up by a photodetector, which converts them back to electrical pulses. These, in turn, are fed into a decoder...
...Fibers have enormous advantages over wires. Because they do not "leak" light as copper wires "leak" electricity, fibers should eliminate the cross talk and static that can occur when one telephone wire spills some of its signal into a neighboring line. Measuring as little as one-thousandth of an inch in diameter, the fibers are also far less bulky than wires -an important consideration in cities, where underground cable conduits are already overcrowded. Eventually, the fibers may also prove cheaper. Supplies of copper are limited; silicon, the chief ingredient of glass fiber, is one of the most plentiful materials...
Field Test. Bell Labs is currently field-testing an experimental fiber-optics communications system in Atlanta. But much work must still be done before glass replaces copper in regular systems. Engineers are still trying to find efficient ways of joining the threadlike fibers together. Researchers are working to increase the lifetime of the lasers used to generate the fine beams upon which optical communication depends; the lasers now in use have a projected lifetime of 100,000 hours; researchers would like to increase this to 1 million hours. Scientists are also developing integrated optical circuits, the optical equivalent...
Police in Bournemouth, England, are now using an optical system developed by International Telephone and Telegraph to link their radio room with a computer data bank that enables them to keep track of their patrol cars. Fiber-optics circuits are being tested as control systems in U.S. military aircraft and ships; a Japanese power company is using fiber-optics circuits, which are not affected by nearby high-tension lines, to control some of its equipment...