City of Light: The Story of Fiber Optics

52 CITY OF LIGHT
in 1925. He was a lively, cheerful man whose interests reached well beyond
physics. He fell in love with the French language and literature while working
in Paris, 25 knew Latin and Greek, and was fluent in English. He also became
fascinated with optics.
The study of optics was hardly fashionable in the 1920s, but van Heel was
keenly aware of its deep roots in Holland. A Dutch spectacle-maker built the
first telescope in the early seventeenth century, and a Dutch scientist formulated
the laws of refraction. 26 Van Heel collected early books on optics; on
one American trip, he made a point of visiting a Library of Congress exhibit
that showed four early volumes on optics missing from his personal library. 27
Bram van Heel was not a trailblazing superstar of science; you must dig
deep to find his name today, although former students remember him fondly.
His genius lay in the demanding fields of precision optical measurement and
lens design. 28 He helped build the Dutch optical industry in the 1930s. After
the war, he salvaged old mechanical telephone relays to build one of the
world’s first computers, which he used for the complex calculations needed
to design lenses. 29
Dutch officials sought his help to rebuild the country’s war-shattered optical
industry and to develop new military optical systems. Willem Brouwer,
a Resistance fighter who had returned to school after the war, joined van
Heel on the periscope project. In late 1949, they intially considered an array
of thin reflective tubes, but soon decided transparent fibers with mirror coatings
would be more efficient. 30 In January 1950, Brouwer fired arrows attached
to drops of molten glass down a long hall, drawing their first glass
fibers the same way Boys had done 60 years earlier. They also made plastic
fibers. Initially, none of them transmitted much light.
Van Heel returned from America enthusiastic about transparent claddings.
31 He and Brouwer first pulled plastic fibers through liquid beeswax, a
material common in mid-century laboratories. It improved fiber transmission
more than they expected. 32 Next they pulled bare fibers through liquid plastic,
stringing them around the lab so the plastic could cure and painting them
black to keep light from leaking between them.
They made imaging bundles by winding a single long fiber around and
around a reel, and cementing the fibers together at one spot. Cutting the
cemented area gave them a flexible bundle with fibers in matching positions
at both ends. An image focused on one end appeared on the other end. By
April 1952, they had sent images through bundles of about 400 fibers as
long as 20 inches (half a meter). 33
Progress was interrupted in early 1953 when Brouwer left for America.
Young, impulsive, and without strong ties to Holland, Brouwer had applied
to immigrate during a moment of frustration in 1950. When approval finally
came in early 1953, it was good for only three months. Van Heel asked him
to stay, but with Europe still recovering from the war, Brouwer saw more
opportunity in America. On the other side of the Atlantic, he abandoned fiber
optics to work on military reconnaissance cameras, and the aerial sextant for
the U2 spy plane.