What is Optical Fiber?
Optical fiber is a term for any sort of plastic or glass conduit meant to transport light. The principles behind optical fiber are actually quite old, but in recent years it has become an incredibly important technology, as communications infrastructure has begun to use optical fiber to transmit data at extremely high rates. Aside from fiber optic communications, however, optical fiber has a number of applications in medicine, consumer products, and physics.
These sorts of fibers offer a number of advantages over traditional metal wire, the most important being that there is considerably less signal degradation. Additionally, optical fiber is immune to electromagnetic interference, which can seriously impede the transmission of data along normal metal wires. This adds an added security measure, as well, since optical fiber can survive an electromagnetic pulse which would destroy metal cables.
The basic principle behind optical fiber is quite simple: the fiber is coated to make it completely reflective on the inside, so that when light goes in, it reflects without losing any light, passing down the fiber to the other end. This basic idea, of guiding light by refraction, goes back to the 1840s. By the beginning of the 20th century some practical applications had been developed, most notably the use of optical fiber in dentistry to light up the inside of the mouth.
In the 1920s, the same basic technology was used to actually transmit full images. In the 1930s that technology was used practically to illuminate the inside of a surgery, allowing for much more precise surgery. Optical fiber continues to be used in surgery, especially to facilitate less invasive internal surgeries. The first true optical fiber appeared in the 1950s, and by the end of the decade experiments were underway with a type of fiber very similar to that used today, with glass fibers coated with a transparent sheath.
By the 1970s, optical fiber was beginning to be refined, reducing the noise in the signal. These refinements allowed for the possibility that the fibers would be able to be used to transmit actual communication over long distances. This allowed for massive communication backbones to be built, which laid the groundwork for the internet. At the dawn of the 1980s, General Electric created a method by which extremely long strands of optical fiber could be stretched out, up to 25 miles (40km) at a time, making massive backbones even easier to construct.
Because of its low level of degradation, or attenuation, optical fiber is ideal for long distance communications. While metal wire requires repeaters to be installed at short distances, to make sure the signal stays strong, optical fiber can be stretched for long distances without a repeater, reducing costs drastically. Additionally, fiber is able to transport a great deal more information than metal wire, making it preferable even over short distances, such as those within a network situation in a single building. And since optical fiber doesn’t conduct electricity in the same way metal wire does, it is safe to use in high voltage environments where traditional wiring could be dangerous.
Written by Brendan McGuigan
