City of Light: The Story of Fiber Optics

236 CITY OF LIGHT
Today’s Technology
The latest generation of submarine cables operating as I write carry ten billion
bits per second through each fiber—2.5 billion bits at each of four wavelengths.
Optical amplifiers simultaneously boost the strengths of all four wavelength
signals in each fiber. Because they use optical amplifiers, that transmission
rate can be multiplied by adding more laser transmitters at additional
wavelengths on each end. The most ambitious system in the works is called
Project Oxygen. It’s a $10 billion global network that is supposed to carry
160 billion bits per second on each fiber—10 billion bits per second at each
of 16 wavelengths. With four fiber pairs, each length of submarine cable will
carry up to 640 billion bits per second. That’s over a thousand times the
capacity TAT-8 offered a decade ago. When it’s up and running in 2003,
Project Oxygen’s 168,000 kilometers (100,000 miles) of cable will connect
99 points in 78 countries. 25
On land, telecommunications companies are multiplying the capacity of
their long-distance systems by adding extra wavelengths. The first systems
used four wavelengths, each operating at 2.5 billion bits per second, to send
a total of 10 billion bits per second. 26 In 1997, MCI started field tests using
four wavelengths each carrying 10 billion bits per second, a total capacity of
40 billion bits per second. 27 By the end of 1998, Lucent Technologies promises
to deliver a system that can pack a staggering 40 billion bits per second—
10 billion bits at each of 40 wavelengths—through a single fiber. 28 Other
companies are not far behind.
In early 1997, I visited FiberFest, an exhibition run by the New England
Fiberoptics Council at a suburban Boston hotel, to keep up with the industry
and chat with old friends. It was just a little local show, but I counted 92
exhibitors—triple the size of the first fiber industry shows I attended back in
1978. The technology ranged from the exotic to the mundane. The Optical
Corporation of America showed its latest devices for wavelength-division multiplexing,
using ideas Will Hicks patented in 1987. 29 Nearby, other tables
showed plastic trays for routing and organizing fiber-optic cables, products
that are useful, but hardly high-tech.
Bundles of imaging fibers are still around. I stopped to look at one on a
table labeled Schott-CML Fiberoptics Inc. It’s a joint venture of the corporate
descendants of American Optical and Jim Godbey’s original fiber-bundle venture,
Electro-Fiberoptics. The bundle is a prototype of a fiberscope for the do-ityourself
market. You can use it to see what went down the drain or to guide
wires through holes in the wall. It’s just what Clarence Hansell was looking
for 70 years ago when he started writing the notes that became his patent
application. If all goes well, you should be able to buy one for under a hundred
dollars soon after this book is in print.
The City of Light has sprawled across the world, vast and complex. I’m
surprised how many people I encounter who know about fiber optics, or even
work with them. By one of the odd coincidences of life, one of C. W. Hansell’s