City of Light: The Story of Fiber Optics

120 CITY OF LIGHT
Military Support
Kao made another early convert in Don Williams of the Royal Signals Research
and Development Establishment in Christchurch. Like the Pentagon,
the British Ministry of Defense was investing heavily in new technology, seeking
new ideas from the likes of Alec Reeves. Military electronics were big
business for ITT in both Britain and America in the 1960s. Millimeter waveguides
and hollow light pipes were far too cumbersome for military use, but
small flexible fibers might replace the thick copper cables that weighed down
portable communications systems. Fibers also had another attraction at a time
when military planners worried about fighting nuclear wars. Nuclear blasts
produce a strong burst of electromagnetic waves that can induce strong current
pulses in metal wires, and those pulses can fry delicate electronics. Fibers
are immune to that effect because they don’t conduct electricity. That made
fibers promising for airplane and ship communication systems that had to
withstand nuclear effects. Because those systems don’t have to carry signals
very far, military systems could function with fibers less transparent than
needed for civilian telephone networks. That was an important boost, because
it opened a market for fiber communications even if loss could not be reduced
to 20 decibels per kilometer.
Williams gave STL a small research grant. The military connection gave
Kao access to sophisticated equipment able to measure important quantities,
such as low levels of impurities in glass. 18 Williams also funded William Alec
Gambling, an electronics professor at the University of Southampton. Gambling
had thought of fiber-optic communications as far back as 1964 19 but
had never done as much analysis as Kao and Hockham. His group concentrated
on large-core fibers because the short, cheap, low-bandwidth systems
wanted by the Ministry of Defense did not require single-mode transmission.
The Traveling Fiber Salesman
Support from Roberts and Williams was a step in the right direction, but only
a step. Charles Kao went on the road to sell others on the case for fiber optics.
He had made his first trip to America while working on his fiber proposal. In
early 1966, he took a second trip to talk with American experts in fiber
fabrication, optical glass, and lasers. He visited Eli Snitzer at American Optical,
glass expert Norbert Kreidl at Rutgers University in New Jersey, the optics
giant Bausch & Lomb in Rochester, and Kapany’s Optics Technology in California.
His stop at Bell Labs was disappointing. Miller’s group at Crawford Hill
was less then enthusiastic. ‘‘They have requested the materials people to investigate
into the possible means of obtaining the very-low-loss materials required.
That was as much as they would do to influence the work of other
departments. They now just have to wait and see. If the low-loss material