A world of information in a filament of glass

Net Results: Forty years ago, on January 27, 1966, to be precise, two engineers in Britain presented a paper that made what many in the assembled audience of engineers considered an outrageous prediction.

Telephone, television and even data might some day travel thousands of miles - even across the widest oceans - on a beam of light through filaments of glass close to the size of a human hair.

The reason for their bravado was that the two - Charles Kao and George Hockham - had made a stunning breakthrough in the nascent area of fibre optics. Up to this point, researchers had been unsuccessful at getting adequate amounts of light to pass cleanly through a glass fibre. Something within the glass seemed to cause obstructions, causing the beam of light to degrade so that it could only travel very short distances - less than 2m (2.18 yards). Many felt this was likely to be an intrinsic quality of glass, and that it was an unsuitable medium for transporting data.

There were other options concerning the use of optics. Researchers were also experimenting with sending light through a metal tube, but due to manufacturing costs, this would be a formidably pricey form of transport. Some researchers thought using lenses built into a telephone could work, but this was clumsy and had limitations.

Using glass fibre seemed ideal, but up to the publication of the 1966 paper, it was perhaps an impossible hope. Thus, when Dr Kao stood up to say there was nothing fundamental in the structure of glass to impede a beam of light, this was potentially revolutionary news.

Theoretically, said Dr Kao, it should be possible to send information along a laser through a thin glass cable, even over great distances, if a way could be found to create pure, clean glass. And if a number of other monumental technical challenges could be resolved.

Their employer promptly issued a press release; its most notable quality being to demonstrate that 40 years ago, technology press releases could be as turgid and dry as anything emanating from the information and communication technologies industry today.

How about this for an opening line to really grab your interest: "Techniques for guiding light energy along special types of optical conductors are under active investigation at Standard Telecommunications Laboratories Limited, Harlow."

Moreover, proving that technology companies have a history of not knowing how to sell their best story, hidden in the "special notes for editors" is this compelling bit: "It should be noted that when these methods are perfected, it will be possible to transmit very large quantities of information (telephone, television, data, etc) between say the Americas and Europe along a single undersea cable."

Dr Kao, who presented the paper's findings to his peers, stuck his neck out and made the dramatic claim that a fibre cable might carry the equivalent content of 200 television channels or 200,000 phone calls.

Of course, the prediction made in a footnote is the fibre optics-filled world that we know today.

But the prediction that might seem obvious to us now was truly daring at the time, according to Philip Hargrave, chief science officer for Nortel's Europe, Middle East and Africa division. "I'm told people at that meeting were very sceptical, but Kao and Hockham turned out to be right," he says.

Nortel has a particular relationship with the 40th anniversary of this fibre optics breakthrough, not just because the company is one of the pioneers in the industry, but also because Standard Telecommunications Laboratories (STL) eventually became part of Nortel.

While the two engineers had proved fibre optics should work in concept, they now had to tackle ways of limiting loss - minimising the degradation of the light beam. By the following year, says Hargrave, they had put together a working demonstration that could send a beam 20m; a big improvement on 2m, but hardly a promising herald of an eventual transatlantic cable.

But Corning Glass in the US took up the challenge of finding new ways of creating purer glass. Soon, they discovered they could create glass through the chemical process of oxidation rather than having to mix it in a container, which had allowed impurities from the container to pollute the glass.

By 1973, researchers could move light 2km, and in 1977 BT installed the first working trial of a fibre telephone network. Light could now travel 2,000km through fibre, as researchers found ways to keep boosting the light signal using generators spaced along the network.

Moreover, as light could be sent in pulses, on or off, this meant it could carry digital information represented in binary digital form. This occurred just in time to dovetail with, and accelerate, the breakthrough that especially benefited from this clean, fast, digital form of transport - the internet.

"By the 1980s and 1990s, fibre began to be deployed in huge amounts all around the world," notes Hargrave.

In the 1980s, Nortel sunk a cable under the sea, finally linking the continents as foreseen in the 1966 paper. By the 1990s, the company was doubling the capacity of fibre every nine months.

As Hargrave notes, just as some of the technologies used reached maximum capability, a new breakthrough would advance fibre optics in a different area, enabling rapid growth. "You could ride Moore's Law," he says.

Fibre has brought us into the broadband world. Now, the goal is to get more intelligence into the network itself, says Hargrave, creating smart networks that self-manage and self-heal.

With some 35 years experience in the fibre optic world, Hargrave says he is currently most intrigued by developments in the radio and wireless area - Wi-Fi and Wi-MAX - yet another arena made possible by high-capacity, highly flexible fibre.

"At the end of the day, it's still just pipes and digits," he says with satisfaction. Happy birthday, then, pipes and digits.