City of Light: The Story of Fiber Optics

BREAKTHROUGH 139
ometer (3280 feet) of fiber without incident, although it broke in two when
Keck rewound it onto a drum for heat treating. Keck concentrated on the
smaller 200-meter (660-foot) segment.
The fiber came out of the heat-treating furnace on a Friday afternoon. It
was early summer, and almost everyone else in the lab had gone home, but
Keck was eager to see the results and worried that the fiber—fragile after
heat treating—might not be in one piece when he returned on Monday. He
set up a test jig that aimed a red helium-neon laser beam into the fiber to
help him align it.
‘‘I remember so vividly moving the fiber over, and when the laser spot hit
the core, all of a sudden I got this flash of light. It was different, a spot that
was different than the laser spot,’’ recalls Keck. That puzzled him; he had
never seen such a spot before, and he didn’t immediately know what it was.
Eventually he realized that the light had gone back and forth through all 200
meters of fiber. The distant end of the fiber reflected 4 percent of the light
that hit it back toward Keck, and that light was passing back through the
fiber to reach his eye. It was still bright after passing through 400 meters
(1320 feet) of fiber. He had before him the clearest glass ever made. Delighted
and excited, he went searching for someone to share his eureka moment. Not
a soul was left in the lab, so he went into the main hallway. He heard an
elevator door open, and out stepped Bill Armistead. Keck invited the research
director to come see ‘‘something neat,’’ showed him the new fiber, and then
went home to enjoy the afterglow of success all weekend. 23
Careful measurements later showed the fiber had attenuation of 16 decibels
per kilometer. This time they had plenty of it. The Corning team pinned
the measurement down so tightly the error was only plus or minus one decibel
per kilometer. It was an impressive achievement and a dramatic improvement
over previous fibers. Don Keck, Bob Maurer, and Peter Schultz had
hit the fiber-optic jackpot.
A Mutually Surprising Announcement
The breakthrough presented Corning with a strategic dilemma. Corning had
built its success in the highly competitive glass industry on new technology,
which for glass usually means new processes. While processes can be patented,
it is hard to make the patents so tight that competitors cannot circumvent
them, so the glass industry had a tradition of jealously guarding its
techniques as trade secrets. This left excited Corning scientists wary about
disclosing details, even to their development partners. Maurer was particularly
cautious because he thought competitors were close on his heels. It
didn’t matter that the British, the Japanese, and Bell Labs were reporting
mediocre results; Maurer assumed that they, like Corning, were keeping their
successes quiet. 24
In fact, everyone else in the low-loss fiber race were telephone companies,
who lived in a different world than Corning. In 1970, phone companies didn’t