An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers are widely used in fiber-optic communication, 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 and ar. History and first demonstrated the guiding of light by refraction, the principle that makes fiber optics possible, in in the early 1840s. included a demonstration of it in his publi. Optical fiber is used as a medium for and because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because propagates. An optical fiber is a cylindrical ( waveguide) that transmits light along its axis through the process of total internal reflection. The fiber consists of a core surrounded by a layer, both.