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Optical Cable

In 1880, an American inventor from Concord, Massachusetts named William Wheeling patented a concept he called "piping light." He believed that, in the same way as water could be distributed through a house via plumbing, light too could be transmitted through a series of pipes.

Fibre optic installation, Jasper Ave and 104 St.In this unusual twist on the optical telegraph, Wheeling felt that, theoretically, light could be used to convey information to a number of places at once. Unfortunately, his invention proved ineffective and was quickly forgotten.

Instead, Alexander Graham Bell’s photophone came closest to predicting both early fibre optic technology and later advances in the free-space optics that allow data transmission through infrared light beams.

Perhaps surprisingly, this technology did not progress much past Bell’s work until the 1950s, when Brian O’Brien, a researcher at the American Optical Company, developed the first image-transmitting fibres. This early development was only marginally effective at transmitting imagery, because the light flashed through it quickly degraded.

Meanwhile, Indian-born Narinder Kapany, working out of England, created the fibrescope out of simple glass tubing. Kapany’s design—wherein light was transmitted through a glass core and protected from degradation by an outer coat of different glass called "cladding"—worked to keep a pure signal within the optical cable.

An outer coating was then added to protect the glass cable from breakage. Information was sent from a transmitter through the cable, via light, to a receiver—in this case, a photodiode—that could translate that signal back into electrical current.

Because this new design was more efficient than the older model, it was soon put to commercial use.

In 1956, Kapany was the first to use the term "fibre optics" to describe this technology.

Gordon Gould, a graduate student at Columbia University in New York City, worked with laser technology, and understood the small and intense beam of light he could generate would be most effective for travelling through fibre optics. The Light Emitting Diode (LED), a device capable of translating electrical current directly into light, could also serve the same purpose.

Light is capable of sending much more information than are radio frequencies, so the communications industry took immediate notice of these new developments. The key was to minimize further the massive light loss that occurred as the beam travelled through the core of optical cable.

The problem was quickly traced to impurities within the glass itself, and 1970 saw the development of glass pure enough to create effective fibre optics.

The US military was among the first groups to make regular use of this technology, through the late 1970s, taking advantage of a new generation that further diminished the amount of light lost.

Broadcasters soon followed suit, albeit more slowly, and the telephone companies became involved later still.

Microscope for joining optic cables Because optical cables were more efficient at sending large loads of data, fibre optics allowed smaller telephone companies to compete more readily with larger ones. The technology spread slowly, however, especially in places accustomed to harsh weather. Various interests within the province of Alberta have worked to increase the availability of this efficient technology.

Alberta SuperNet provides an example of how fibre optics can be used to provide quick connections for large numbers of people.


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