Fiber Optics

Revision as of 15:30, 31 December 2008 by Azalma (talk | contribs)

Fiber Optics

Fiber Optics.jpg

The invention of the laser in the early 1960s spawned a field of engineering known as optoelectronics, which grew steadily in the 1980s and 1990s. Many engineers believed that the laser would be useful for transmitting information through the air, but they soon learned that clouds, rain, and other atmospheric conditions sometimes blocked the beam. An alternative was to send laser light along glass fibers (similar to the way electric signals are sent along copper wires).

The idea of using fibers to telecommunication was first considered by K.C. Kao and G.A. Hockham in England in 1966.  Robert Maurer, Donald Keck and Peter Schultz, working at Corning, developed the first optical fiber capable of transmitting over substantial distances in 1970 and by 1976, Corning was offering a commercial product. But it was still difficult to make glass fibers that were capable of carrying pulses of light for very long distances without weakening the signal. This remained the case until the early 1980s. 

Engineers installed an experimental fiber optic system in 1976. Using a gallium-arsenide semiconductor laser, the AT&T company installed an experimental 2000-meter-long (1.25-mile-long) fiber optic cable under the streets of Atlanta, Georgia. By 1983 improved fibers allowed AT&T to install a cable from New York to Washington, DC. The maximum practical cable length continued to grow, and by 1988 U.S and British engineers had completed the first trans-Atlantic optical cable. This was the first of many such undersea cables around the world, and its installation benefited from over a hundred years of experience in laying undersea telegraph and telephone cables.

In the 1980s, engineers assumed that optical cables would replace more expensive copper cables for telephone service, saving money in the process. When the use of the Internet exploded in the 1990s, suddenly there was a great demand for cables that could carry heavy loads of digital data. Optical fiber fit the bill perfectly, and many thousands of miles of new cable have been laid all around the world. In fact, the demand for ordinary copper cables for use in telephone and data transmission has decreased considerably because of optical fiber. Today, optical fiber serves as the “backbone” for our communication services, with copper wire, cell phones, or other technologies serving only the very “ends” of the network.