TRANSMITTING LIGHT THROUGH FIBERSTRANSMITTING LIGHT THROUGH FIBERSSome of the more common terms used to describe optical fiber are a "light tube" or a "conduit for light." These terms have led a lot of people to think that there is some type of hole in the middle of an optical fiber. This is not the case.None the less, optical fiber does function as a "tube" or "conduit" for light. Light does flow down the center of a fiber (the core) like water flows through a pipe. As you can see in Fig. 11.1, there are three concentric layers to an optical fiber.
Terrell Croft; Frederic P. Hartwell; Wilford I. Summers: American Electricians' Handbook, Sixteenth Edition. TRANSMITTING LIGHT THROUGH FIBERS, Chapter (McGraw-Hill Professional, 2013), AccessEngineering