Attenuation and Bandwidth characteristics of different fiber optic cable candidates Figure illustrates the variation of attenuation with wavelength taken over an ensemble of fiber optic cable material types. The three principal windows of operation, propagation through a cable, are indicated.
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. 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. 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.
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.
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.STEP INDEX FIBER: The refractive index of the core is uniform throughout and undergoes on abrupt change at the core cladding boundary GRADED INDEX FIBER: The refractive index of the core is made to vary gradually such that it is maximum at the center of the core.
Fiber Optic Tutorial. What are Fiber Optic Cables? Fiber optic cables consist of a glass core and cladding, buffer coating, Kevlar strength members and a protective outer jacket. 1.
Step index fiber. 2. Graded index fiber. Let us discuss the difference between the two: 1. Step index fiber is of two types viz; mono mode fiber and multi mode fiber.
Graded index fiber is of only of one type that is multi mode fiber. 2. The refractive index of the core of . OM4 fiber is the latest develop-ment in this series. It is espe-cially well suited for shorter reach data center and high per-formance computing applica-.
The refractive index of the core of step index fiber is constant throughout the core. The refractive index of the core of the graded index fiber is maximum at center,core and then it decreases towards core-Cladding interface.
In fact, step-index multimode fiber is less common than graded-index, and most manufacturers’ default option for multimode fiber is graded-index. M2 Optics offers premium multimode fiber from manufacturers such as Corning ® and OFS ®, and we customize each module per customer requests.