City of Light: The Story of Fiber Optics

BREAKTHROUGH 133
heat them slightly. Silicon tetrachloride evaporates readily because of its low
boiling point, but the chlorides of troublesome impurities have much higher
boiling points and stay behind. For example, molecules of iron chloride are a
thousand trillion (10 15 ) times less likely to evaporate than silicon tetrachloride.
6 Inject the silicon tetrachloride into a flame where hydrogen burns in
oxygen to form water, and the silicon tetrachloride splits the water molecules.
Hydrogen chloride remains in the air (but has to be removed as a pollutant).
A thick white ‘‘soot’’ settles out, silica containing just parts per billion of
impurities.
In Hyde’s time, the main attraction of fused silica was its low thermal
expansion. In 1939 another Corning scientist found that adding titania (titanium
dioxide) to fused silica could reduce its thermal expansion almost to
zero near room temperature. In the early 1950s, Corning started making
large pieces of ULE (for ultra low expansion) glass and built a small but
healthy business selling it for demanding applications including telescope mirrors
and spy satellites. 7 (It also is used in Corningware ceramics.)
Research remained important at Corning, which in 1963 moved its scientists
into a sparkling new glass-walled complex designed by the same architect
as the sprawling Bell Labs building in Holmdel. Sitting on a hillside
outside of the town of Corning, it overlooks the Chemung River valley, where
the company began.
A Worry Catalog
Bob Maurer was a logical choice to seek the clearest of glasses. Born July 20,
1924, in St. Louis, he grew up in Arkansas and earned a doctorate in lowtemperature
physics from MIT before joining Corning in 1952. By the mid-
1960s, he had thoroughly settled in rural western New York. He had spent
a decade on glass research and managed a small glass development group.
Maurer had tried to make lasers by doping glass with the rare earth europium.
In the course of that work, he had met Eli Snitzer, who had taught him to
view optical fibers as waveguides.
In his systematic way, Maurer collected information. Optical fibers were
not new to Corning; a plant in the valley had begun making fiber-optic faceplates
in 1963. 8 Chuck Lucy, who was in charge of that product line, became
the corporate sponsor of Maurer’s research. 9 Maurer talked with the Corning
fiber engineers, although he knew communication fibers would require a different
technology. He asked Stew Miller at Bell Labs about communications. 10
He quizzed Shaver about his visit to Britain, and when others followed Shaver,
he talked with them.
He also began investigating on his own. He had two men in his group,
Jack Stroud and Guy Stong, study the loss in bundled fibers. They concluded
it came mostly from defects formed during fiber fabrication. To some extent
that was good news; if imperfections caused the loss, better fiber fabrication
should reduce it.