Definition: Fiber optic is a filament of a dielectric material that has transparency to a portion of the optical spectrum and structure so that light is propagated through the fiber. It consists of a central core surrounded by a cladding. In a typical step-index fiber, the core has an index of refraction
that is slightly higher than that of its surrounding cladding
. In a ray-optics model, illuminating the end of the fiber starts rays along many possible paths in the core and cladding. A ray whose path meets the core-clad boundary at a small enough angle is reflected back into the core, and thereby, is confined to the core by a series of total internal reflections and such a ray may thus propagate for long distances (>km) in the fiber core. Similar principles apply to graded-index fiber optics for which the transition between
and
is gradual.
Alternative definition:
Synonym: optical fiber, glass fiber, optical guide
References: Optical Materials: Volume 1. Optical Materials. Taylor & Francis, 1990
https://doi.org/10.1201/9781003210139
Related terms:
