Wikipedia
An optical fiber (or fibre in British English) is a flexible, transparent fiber made by drawing glass (silica) or plastic to a diameter slightly thicker than that of a human hair Optical fibers are used most often as a means to transmit light between the two ends of the fiber and find wide usage in fiber-optic communications, where they permit transmission over longer distances and at higher bandwidths (data transfer rates) than electrical cables Fibers are used instead of metal wires because signals travel along them with less loss in addition, fibers are immune to electromagnetic interference, a problem from which metal wires suffer
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