City of Light: The Story of Fiber Optics

196 CITY OF LIGHT
In January 1980, AT&T asked the Federal Communications Commission
to approve construction of the $79 million system. 92 The designers played it
safe. In its first stage, the system would send one 45 million bit channel per
fiber at 825 nanometers. Later, they proposed to add two more channels per
fiber at different wavelengths, 875 nanometers and 1.3 micrometers. (Signals
went only one way through each fiber.)
The idea, dating back to the light-pipe schemes of the 1960s, was that
each wavelength could carry an independent signal through the fiber, with
optics at the far end directing them to different receivers. Will Hicks was
playing with the same concept of wavelength-division multiplexing in his loft
but using single-mode fiber. He thought Bell’s choice of graded-index fiber
was stupid and said as much in a letter to the president of AT&T in which
he predicted it would be the last graded-index installation in America. AT&T
never responded. 93 Corning also suggested using higher-capacity single-mode
fiber in a complaint filed with the Federal Communications Commission. 94
However, the central issue for Corning was not the choice of technology
but the decision of who should build the system. AT&T wanted the job to go
to its Western Electric subsidiary (now the separate Lucent Technologies).
Corning argued that competitive bidding was vital to a healthy American
industry. Not surprisingly, Corning’s main concern was its own health—it
had to sell fiber to make money, and AT&T was its biggest potential customer.
If the phone company made its own fiber, Corning would be shut out of the
market. The FCC, starting to like the idea of competition, bought Corning’s
argument for open bids. It allowed AT&T to build part of the system from
New York to Washington but insisted on open bidding for the rest. 95
The Boston–New York segment attracted bids from Europe and Japan as
well as America. AT&T decided to stay with three wavelengths through
graded-index fibers. A major reason was that Bell did not trust the longevity
of 1.3-micrometer lasers. Its design called for lasers at 825 and 875 nanometers
and an LED at the longer wavelength, with the same repeater spacing
on all three channels. 96 Intense political maneuvering followed the bidding,
and in the end the foreign-owned winners were disqualified in favor of Western
Electric. 97
Fiber technology moved steadily forward as AT&T assembled the system.
Transmission at 825 nanometers was doubled to 90 million bits per second
before the hardware went in. Long-wavelength lasers made the grade, so
AT&T used them to transmit 180 million bits per second and never bothered
with 875 nanometers. 98 That brought total capacity to 270 million bits per
second per fiber.
But the wheels of progress ground slowly at the FCC, the courts, and the
giant telephone company. It took years to approve, build, and install the
system. The world had changed by the time the whole Northeast Corridor
was up and running in 1984. The Bell System had split into AT&T and seven
regional operating companies, and competing long-distance companies had
begun sending 400 million bits per second through single-mode fibers. The
Northeast Corridor was almost instantly obsolete.