Optical fiber

Light-conducting fiber

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 cables because signals travel along them with less loss and are immune to electromagnetic interference.

From Wikipedia, under CC BY-SA. More on occurri.