City of Light: The Story of Fiber Optics

58 CITY OF LIGHT
Hopkins knew he needed more time and money to make imagetransmitting
bundles, so in July 1952 he asked the Royal Society for a grant
of £1500 a little over half earmarked to pay a graduate assistant. He got the
grant in three months and offered the assistantship to Narinder S. Kapany,
an ambitious Indian national who had asked earlier about graduate study.
The selection was as much political as academic; Hopkins felt ‘‘very much
motivated, as indeed were many liberal-minded people at that time, by sympathy
for someone who had come from part of Britain’s imperial past.’’ 67 It
would prove a fateful choice.
Born in 1927 in Moga, Punjab, Kapany still wears the untrimmed beard
and turban traditional for followers of the Sikh religion. Raised in a welleducated
upper-class family, he grew interested in optics after his father gave
him a box camera in high school. He had attended an Indian university and
worked in a military optics factory, then studied optics for a year at Imperial
College, and worked for a Glasgow optics company. He hoped eventually to
return to India to start his own optical business. 68 He jumped at the chance
to work with Hopkins.
The two started with 25-micrometer (0.001-inch) glass fibers that had
been made for glass cloth. The fibers carried light only 75 centimeters (30
inches), but Hopkins thought that would suffice for a demonstration. Neither
he nor Kapany thought of cladding the fibers.
The biggest challenge, to Hopkins’ mind, was assembling 10,000 to
20,000 fibers into a bundle with their ends aligned to carry an image. 69 It’s
the sort of task that sounds mundane until you try it. The idea was simple.
First he and Kapany wound a fiber thousands of times around a spool, then
clamped the looped fiber at several points and unscrewed one side of the spool
to remove the loop. Next they cut the loop at the clamps, yielding bundles
four inches (ten centimeters) long, with fibers clamped at the ends but loose
in the middle. They checked the bundles by looking through them at a razor
blade; if they saw a straight line, the fibers were in the right places. They
spent months assembling equipment to wind fibers and getting it to function
properly.
In November 1953, they sent a letter to Nature, 70 which published it on
January 2, 1954, just below van Heel’s long-delayed letter. It’s not uncommon
for journal editors to group papers on the same topic—the mystery is
the timing. The journal received van Heel’s letter May 21, and normally it
would have appeared months before the one from Hopkins and Kapany was
received on November 22. Suspicious minds suspect Hopkins was asked to
referee van Heel’s paper and delayed it until he could submit his own. In fact,
Brouwer says that when van Heel asked about the delay, the journal referred
him to Hopkins as its letters editor. 71 (Nature has no records from that period.)
72 Yet before his death, Hopkins denied responsibility, saying he did not
see van Heel’s paper until shortly before it appeared, when Nature noted the
similarities and sent each author copies of the other’s paper. 73
The two Nature papers do not reference each other and take rather different
approaches. Van Heel concentrated on transparent coatings, mentioning im-