Fiber optics are long tubes with a transparent core used to transmit light. They are most commonly used with infrared light to efficiently transmit electronic information over many miles. Many people are more familiar with their decorative uses, however. Fiber optics are used in artificial Christmas trees, toys, industrial lighting and many other applications.
Fiber Optic Structure
The core of a fiber optic cable is a thin, flexible, transparent glass or plastic tube. Around this tube is a reflective layer, and around that layer is a coating to protect the fiber optic cable. At places where light is supposed to shine out from the cable, there is no reflective layer or coating around the glass.
How Fiber Optic Lighting Works
A light shines into the end of the fiber optic tube, making a beam that travels down. As it moves down the fiber optic line, the beam scatters but the coating reflects it back, sending it down the tube without losing any light. When the light reaches the end of the fiber optic tube, it continues to travel forward, making a little point of light. If a section of the cable is uncovered, some of the light will leak out of it, since there is no reflective coating to send it back into the cable.