Are you new to the field of optical fibers, or just curious about what they are? This article is an entry point to the basic working principles of optical fibers and a sneak peek of the wide world of optical fibers applications.
The Basic Principles of an Optical Fiber
Since the dawn of civilization, humans have been using light as a signal for information or as a communication method. Think of the light of a fire seen from afar, a light house to guide ships, or even different colored smoke signals for visual communication over a long distance.
With light travelling at the fastest possible speed in the universe, it’s no wonder scientists and engineers have always tried to use it to transmit information and messages.
The first published works on the underlying physical principles that led to optical fibers date back at least 1840, where the refraction of light was starting to be understood. This is the phenomenon that makes light move at different speeds in different materials. Modern uses of optical fibers began much later, in the 1960’s, one limiting factor being the complex process needed to manufacture optical fibers.
Guiding light over long distances is complex, since you can lose some of it if your material is not completely transparent, and it can reflect or dim if hitting an interface. In order to overcome this, we make use of a phenomenon known as total internal reflection that enables us to “capture” light.
Here’s how it works: If light travelling in one transparent material arrives at the interface of another transparent material, a portion of it will be reflected and a portion will pass through. Some small quantity of light will also be absorbed in the material, while a portion will be scattered more randomly. The behavior of the light is determined by the refractive index and chemical proprieties of both materials.