Fiber optic technology experienced a phenomenal rate of progress in the second half of the twentieth century. Early all-glass fibers experienced excessive optical loss, the loss of the light signal as it traveled the fiber, limiting transmission distances. This motivated scientists to develop glass fibers that included a separate glass coating.
Summary Chapter Description Vivek Alwayn discusses in this chapter the increasing demand of optical-fiber and its wide spread applications ranging from global networks to desktop computers. Today more than 80 percent of the world's long-distance voice and data traffic is carried over optical-fiber cables.
Fiber-optic cables are constructed of three types of materials: Linear characteristics include attenuation and interference. Fiber-optic cables might have to be spliced together for a number of reasons.
First and foremost, the designer must determine whether the cable is to be installed for an inside-plant ISP or outside-plant OSP application. A Brief History of Fiber-Optic Communications Optical communication systems date back to the s, to the optical semaphore telegraph invented by French inventor Claude Chappe.
InAlexander Graham Bell patented an optical telephone system, which he called the Photophone. However, his earlier invention, the telephone, was more practical and took tangible shape.
The Photophone remained an experimental invention and never materialized.
Hopkins separately wrote papers on imaging bundles. Hopkins reported on imaging bundles of unclad fibers, whereas Van Heel reported on simple bundles of clad fibers. Van Heel covered a bare fiber with a transparent cladding of a lower refractive index. This protected the fiber reflection surface from outside distortion and greatly reduced interference between fibers.
Abraham Van Heel is also notable for another contribution. Stimulated by a conversation with the American optical physicist Brian O'Brien, Van Heel made the crucial innovation of cladding fiber-optic cables.
All earlier fibers developed were bare and lacked any form of cladding, with total internal reflection occurring at a glass-air interface. Abraham Van Heel covered a bare fiber or glass or plastic with a transparent cladding of lower refractive index.
This protected the total reflection surface from contamination and greatly reduced cross talk between fibers. Byglass-clad fibers had attenuation of about 1 decibel dB per meter, fine for medical imaging, but much too high for communications.
InElias Snitzer of American Optical published a theoretical description of a fiber with a core so small it could carry light with only one waveguide mode.
Snitzer's proposal was acceptable for a medical instrument looking inside the human, but the fiber had a light loss of 1 dB per meter. Communication devices needed to operate over much longer distances and required a light loss of no more than 10 or 20 dB per kilometer.
Bya critical and theoretical specification was identified by Dr. Kao for long-range communication devices, the 10 or 20 dB of light loss per kilometer standard.
Kao also illustrated the need for a purer form of glass to help reduce light loss. In the summer ofone team of researchers began experimenting with fused silica, a material capable of extreme purity with a high melting point and a low refractive index.
Corning Glass researchers Robert Maurer, Donald Keck, and Peter Schultz invented fiber-optic wire or "optical waveguide fibers" patent no. By June ofRobert Maurer, Donald Keck, and Peter Schultz invented multimode germanium-doped fiber with a loss of 4 dB per kilometer and much greater strength than titanium-doped fiber.
ByJohn MacChesney developed a modified chemical vapor-deposition process for fiber manufacture at Bell Labs. This process spearheaded the commercial manufacture of fiber-optic cable. In AprilGeneral Telephone and Electronics tested and deployed the world's first live telephone traffic through a fiber-optic system running at 6 Mbps, in Long Beach, California.
They were soon followed by Bell in Maywith an optical telephone communication system installed in the downtown Chicago area, covering a distance of 1. Each optical-fiber pair carried the equivalent of voice channels and was equivalent to a DS3 circuit.
Please check back later.A Brief History of Fiber-Optic Communications—This section discusses the history of fiber optics, from the optical semaphore telegraph to the invention of the first clad glass fiber invented by Abraham Van Heel. Today more than 80 percent of the world's long-distance voice and data traffic is carried over optical-fiber cables.
COURSE TITLE START DATE-END DATE; CCIE Routing & Switching: Lab Exam Preparation: Nov 5, -Nov 16, IT Essentials: PC Hardware & Software (A+). History of optical fiber light transmission, The Nineteenth Century and including Graham Bell's photophone up to light-emitting diodes lasers and Dense Wavelength-Division Multiplexing (DWDM) to supply video on demand and fiber-to-home (FTTh) also known as FTTx and FTTc for fiber optics applications.
Fiber U "The Basics" Self-Study Programs Basic Fiber Optics May be used as preparation for the CFOT® Exam This is a part series of self-study lessons covering the basics of fiber optics.
Corning's extensive work with fiber, coupled with Siemen's cabling technology, helped launch a new era in optical fiber cable and associated products. Today, Siecor is a world leader in the manufacturing of fiber optic cabling system products for voice, data and video communications applications.
Fibre optics: Fibre optics, the science of transmitting data, voice, and images by the passage of light through thin, transparent fibres.
In telecommunications, fibre optic technology has virtually replaced copper wire in long-distance telephone lines, and it is used to link computers within local area networks.