City of Light: The Story of Fiber Optics

A DEMONSTRATION FOR THE QUEEN 165
The telephone monopoly was a giant battleship, steering full steam ahead
into its carefully planned future. From the captain’s tower of top management,
Picturephone seemed merely a little behind schedule. Other unpleasant
realities were easy to mistake for patches of choppy water. Long-distance
traffic slumped along with the economy. Angry consumer advocates and upstart
MCI challenged Bell’s telephone practices and long-distance monopoly.
Looking back, we can see the well-planned future starting to unravel, but
those on board the great ship didn’t spot the icebergs on the horizon.
Nor did Bell Labs worry, at least initially. AT&T’s well-oiled invention machine
had earned a Nobel Prize for the transistor and scored a technical
triumph by demonstrating the first communications satellite. After years of
development, the labs had turned Picturephone over to manufacturing and
the millimeter waveguide to final field trials. Millions of dollars invested in
gas lenses and hollow optical waveguides had yielded only modest success,
but no one expected overnight miracles. Management was convinced they
had the best and brightest scientists on the job, and no one could do it better.
In short, Bell Labs was not merely fat and happy, but growing complacent
and overconfident. The ‘‘not invented here’’ syndrome was rampant; many
managers didn’t want to hear ideas that came from outside what they considered
the world’s premier industrial laboratory. That made fiber optics a
hard sell for Charles Kao and F. F. Roberts. They succeeded by convincing
Bell that fiber might fill the vital but unglamorous role of linking telephone
switching centers a few miles apart. Small and flexible, optical fibers could
thread easily through the underground ducts that carry phone lines in urban
and suburban areas, an impossible task for bend-sensitive millimeter waveguides
and hollow optical waveguides.
Yet Bell still saw fiber playing a secondary role to the more glamorous
high-capacity systems running between cities. Bell was sure glass could never
be as transparent as air. Detlef Gloge calculated hollow optical waveguides
would have loss below one decibel per kilometer, so they could carry light
over 20 times farther than fibers with loss of 20 decibels per kilometer. 30
Fibers might go a mile or two, but waveguides would run from city to city,
carrying signals at rates far higher than optical fibers. ‘‘The scale on which
an optical intercity system will become useful is in the range above 500,000
two-way voice channels, or equivalently over 5,000 two-way video telephone
channels,’’ Miller wrote in 1970. That meant carrying 60 billion bits a second,
although eventual capacities might be a hundred times larger. 31 He expected
individual fiber links to merely carry ‘‘a single video telephone signal,
or a hundred or so voice channels’’ within urban or suburban areas.
A Low-Profile Program
Bell stepped up the pace of its fiber-optics program after learning of the Corning
breakthrough, but it did not change its direction. As Kao had originally