Optical Fiber

A type of optic comprised of a core surrounded by a relatively thin cladding layer of lower index material. This geometry causes internal reflection of light inside the fiber and defines the maximum angles accepted by the fiber. An optical fiber emits into a cone of equal angle, not as a beam of light. Coherent fiber bundles can relay images from one end to the other; whereas, incoherent bundles are used for propagation of light alone.