City of Light: The Story of Fiber Optics

12
Recipes for Grains of Salt
The Semiconductor Laser
(1962–1977)
Jack Tillman said ‘‘Did you know the semiconductor laser
has just been invented? ...Ithink we should get some and
see if they’re any use at all for communications.’’ So I went
over [in 1963 to the Joint Services Electronics Research Laboratory
in Baldock, north of London] for a month, and
brought some of these things back with me. They only operated
at liquid nitrogen temperature, only operated in
pulses of about 10 microseconds, and it took 100 amperes
in each pulse to drive the bloody things. We concluded
that they weren’t very promising.
—David Newman, British Post Office
Research Laboratories 1
A s Corning all too keenly recognized, clear optical fibers were not the only
building block vital for fiber-optic communications. A second crucial
ingredient was a matching light source. From Bell Labs to the British
Post Office, developers of optical communication systems thought the ideal
light source would be a semiconductor laser. By a curious coincidence, the
spring and summer of 1970 also marked symbolic breakthroughs on the
semiconductor laser frontier, although as with fibers, practical devices took
longer.
The allures of semiconductor lasers were considerable. One was the sheer
magic of solid-state devices. Semiconductor technology was hot in the 1960s;
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