City of Light: The Story of Fiber Optics

INTRODUCTION 9
(500 yards) because the signal weakens with distance. Those amplifiers keep
cable technicians busy. You don’t need them with fiber, so cable-television
companies are replacing their old coax with fiber-optic cables.
The huge information capacity of optical fibers changes the ground rules
of telecommunications, which the telephone defined early in the twentieth
century. What seemed adequate pipeline then today delivers only an electronic
trickle in a world parched for information. The telephone network was
engineered to manage information as carefully as nomads husband the scarce
waters of the Sahara. The huge capacity of fibers promises to irrigate our dry
lands, but first we must find uses for the flow that will justify the costs of
extending the data pipeline all the way to our homes. We value information
almost instinctively, like desert nomads think water is a ‘‘good thing,’’ but
faced with an overwhelming abundance, we are as lost as a Bedouin by the
sea. We have long dreamt of making the desert bloom, but we don’t know
how.
The Roots of Fiber Optics
I discovered fiber-optic communications when the technology was still young
and the City of Light was but a small town. Some early settlers are still
around, active developers of new technology or elder statesmen. Others have
died or moved on. As the field has grown, many new people have joined it.
Awareness of fiber optics has spread around the world like the glass threads
themselves. The field and the technology have not stopped growing. Even as
I put the finishing touches on this book, I heard of new advances that promise
even better fiber-optic systems in coming years.
Where did this technological revolution come from? How did it grow so
fast, out-competing older and better-funded projects? This book tells the story,
one more fascinating than I imagined when I started.
In studying fiber optics, I have learned how technology evolves, like life
itself. The idea began as little more than a parlor trick, guiding light in jets
of water or bent glass rods to make physics lectures more entertaining.
Brighter electric lights powered illuminated fountains that awed visitors to
the great Victorian exhibitions, who were accustomed to faint gas lights.
Later, bent rods of glass or plastic guided light to illuminate teeth for dental
exams.
Another generation of engineers adapted light guiding, assembling arrays
of thin, flexible glass fibers to look into inaccessible places. The market niche
was not filled until developers found how to keep light from leaking between
fibers. Once that innovation was perfected, the technology of fiber bundles
evolved rapidly, like animals that had just arrived in a new, unpopulated land.
New applications proliferated in the late 1950s and 1960s, from looking
down the throat to military imaging systems.
Flexible bundles of optical fibers let physicians reach into otherwise inaccessible
parts of the body. Surgeons threaded fiber-optic endoscopes down