The Physics
Factbook
An encyclopedia of scientific essays

Diameter of an Optical Fiber

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Bibliographic Entry Result
(w/surrounding text)
Standardized
Result
Hecht, Jeff. Understanding Fiber. 2nd ed. Indianapolis, IN: Sams, 1993. "The most common optical fibers used in communications are 0.25 to 0.5 mm in diameter, but that includes a coating that protects the fiber from plastic mechanical damage. The cladding, the outer part of the fiber proper, normally is 125 microns across." 250โ€“500 µm
(w/coating)
125 µm
(w/o coating)
"Fibre Optics." Encyclopaedia Britannica. Vol. IV. 1974. "Glass or plastic filaments are spun into diameters that vary from 5 to 100 microns." 5โ€“100 µm
(w/o coating)
Hecht, Jeff. Optics: Light for a New Age. New York: Scribners, 1987. "Most single fibers are.125 mm in diameter, but normally they are coated with plastic that makes them 0.25 to 0.5 mm thick." 250โ€“500 µm
(w/coating)
125 µm
(w/o coating)
Chynoweth, Alan G. "The Fiber Light Guide." Physics Today. May 1976, 218-224. "In a typical situation a 1 cm diameter preform is drawn down into a fiber with an outside diameter of about 100 microns." 100 µm
(w/o coating)
Safford, Edward L. & John A. McCann. Fiberoptics and Laser Handbook. 1st ed. Blue Ridge Summit: TAB, 1984. "The optical fiber … It is a very fine strand of very special glass which may be only 125 microns in diameter." 125 µm
(w/o coating)

With the advent of the fiber-optic network, our world has entered into a new age of communications. Optical fibers are extremely thin strands of glass, which are made up of many layers. They use laser light to carry information, sounds and images over very large distances. Optical communications systems have the capability of carrying thousands of telephone calls or television programs simultaneously, which is just one of their superior aspects in comparison to our current systems. Fiber-optic networks are quicker in transmitting data and make it possible to transmit this data further distances (up to 100 miles with out being quot;boosted"). As well as being safe (they are not affected by lightning, power lines etc. and are difficult to tap), they are static-free, quite space-efficient and are exceptionally strong; "Theoretically, one square inch of optical fiber suspended in mid air, could support 216 six ton elephants in a stationary elevator!"However, there is one downside to this near-perfect technology; although its base product is glass, a very inexpensive material, the cost to implement the fiber-optic systems will be rather high.

The optical fiber, in it's.0005 meter diameter entirety, is made up of three layers, the core, cladding, and the coating. The core is the center of the fiber, which is made of pure glass. This is the region in which the laser light carrying the images, sounds, or data travel at the speed of light. The cladding is also made up of glass, however, this layer is constructed of even purer glass, which keeps the light trapped in the core due to the principal of "total internal reflection"and allows it to "bend"around curves in the fiber -- another incredible property of these optical wonders. The coating is made of a plastic like material called acrylate, which acts to protect the inner glass fiber.

The most amazing aspect of the optical fiber, despite its impressive list of properties, would have to be its minuscule size. Considering that these fibers are now being laid out across the world and will soon be our foremost system of communication, along with the fact that they are capable of carrying such large amounts of information in such an efficient manner, comparing their diameter to that of a human hair seems quite unbelievable! However, the total diameter of a common optical fiber, including the plastic coating is said to be from.00025 to.0005 meters, the estimated diameter of a human hair. The cladding has an approximate diameter of.000125 meters, and the center core, where the laser light reflects, a diameter of.000008 meters to.000625 meters.

Lauren Boyd -- 1997