City of Light: The Story of Fiber Optics

272 CITY OF LIGHT
1971–1972: Focus shifts to graded-index fibers because singlemode
offers few advantages and many problems at
850 nanometers.
June 1972: Maurer, Keck, and Schultz make multimode germania-doped
fiber with 4 decibel per kilometer loss
and much greater strength than titania-doped fiber.
Late 1972: STL modulates diode laser at 1 billion bits per second.
Bell Labs stops work on hollow light pipes.
December 1972: John Fulenwider proposes a fiber-optic communication
network to carry video signals to homes at
International Wire and Cable Symposium.
1973: John MacChesney develops modified chemical vapor
deposition process for making fiber at Bell Labs.
Mid-1973: Diode laser lifetime reaches 1000 hours at Bell Labs.
Spring 1974: Bell Labs settles on graded-index fibers with 50 to
100 micrometer cores.
December 7, 1974: Heinrich Lamm dies at 66.
January 1975: First technical meeting, Topical Conference on Optical
Fiber Transmission, Williamsburg, Virginia.
February 1975: Bell completes installation of 14 kilometers of millimeter
waveguide in New Jersey. After tests, Bell
declares victory and abandons the technology.
June 1975: First commercial continuous-wave semiconductor laser
operating at room temperature offered by Laser
Diode Labs.
September 1975: First nonexperimental fiber-optic link installed by
Dorset (UK) police after lightning knocks out their
communication system.
October 1975: British Post Office begins tests of millimeter waveguide;
like Bell it declares the tests successful, but
never installs any.
1975: Dave Payne and Alex Gambling at University of
Southampton calculate pulse spreading should be
zero at 1.27 micrometers.
January 13, 1976: Bell Labs starts tests of graded-index fiber-optic system
transmitting 45 million bits per second at its
plant in Norcross, Georgia. Laser lifetime is main
problem.
Early 1976: Valtec launches Communications Fiberoptics division.
Early 1976: Masaharu Horiguchi (Nippon Telegraph Telephone
Ibaraki Lab) and Hiroshi Osanai (Fujikura Cable)
make first fibers with low loss—0.47 decibel
per kilometer—at long wavelengths (1.2 micrometers).