If you were to look at a single optical fiber, magnified, you would see that it is made up of the following parts:



?Core: Thin glass center of the fiber where the light travels

?Cladding: Outer optical material which surrounds the core and reflects the light back into the core.

?Buffer coating: Plastic Coating that protects the fiber from moisture and damage.

Thousands of these optical fibers are arranged in bundles to make up optical cables. There are two types of optical fibers; Single-mode fibers, which have small cores and transmit infrared laser light and Multi-mode fibers, which have larger cores and transmit infrared light from light-emitting diodes (LEDs).

How Optical Fibers Transmit Light

Shining a light through a straight tube is easy; simply point the light at the tube; light travels in straight lines, so it's easy. If the tube should bend, one would need a mirror to reflect the light around the turn. If the tube has lots of bends, then it would require more mirrors, to bounce the light from side to side, through the tube. This is essentially what happens in a optical fiber.

Through a principle called total internal reflection, the light in a fiber optic cable travels through the core as it bounces off the mirror-lined cladding. The light wave can travel great distances because the cladding does not absorb any light from the core.

Some of the light signal can degrade within the fiber due to impurities in the glass. The extent that the signal degrades depends on the purity of the glass and the wavelength of the transmitted light. Some premium optical fibers show much less signal degradation than others.

Fiber-Optic Relay System

Fiber optics allow for communication to take place over very long distances. The fiber-optic relay system is made up of the following:

?Transmitter: Produces and encodes light signals

?Optical fiber: Carries light signals

?Optical regenerator: Boosts the light signal over very long distances

?Optical receiver: Receives and decodes the light signals

The transmitter is close to the optical fiber and may even have a lens to focus the light into the fiber. Some signal loss occurs when light is transmitted through the fiber over very long distances; therefore, one or more optical regenerators is spliced along the cable to boost the signal. The optical regenerator is made up of fibers with a special coating called doping, which is ?pumped? with a laser. When a weakened signal comes into the doping, the energy from the laser allows the doped molecules to become lasers and emit a new, stronger light signal with the same characteristics as the incoming weak signal. The optical receiver decodes the incoming digital signals, using a photocell or photodiode.

Benefits of Fiber Optics

The technology of fiber optics has proven to be essential in telecommunications. Compared to copper wire, optical fibers are less expensive. Because optical fibers are thinner than copper wire, more fibers can be bundled into a cable, allowing more lines to go over the same distance, transmitting a larger variety of signals, such as more channels to your cable TV box. Fiber optics experience less signal degradation than copper wire; therefore, requiring lower power transmitters, reducing energy costs. Unlike electrical signals in copper wires, light signals from one fiber do not interfere with other fibers within the same cable; therefore, you get better TV reception and phone conversations are clearer. Optical fibers are ideal for transmitting digital information which is essential for computers. Fiber optics is safer because there is not electricity being passed through the fibers; therefore, not fire hazard. Because they are lightweight, cables take up less space.

Because of the many advantages of fiber optics, the technology is used in other industries besides telecommunications and computers. Because they are flexible, they can transmit and receive light using flexible digital cameras for use in medical imaging (endoscopes, laparoscopes), mechanical imaging (to inspect mechanical welds in pipes and engines in airplanes, rockets and space shuttles, and plumbing, to inspect sewer lines.

The technology of fiber-optics has revolutionized telephones, computers, cable TV, digital cameras, medical equipment and much more. Like most forms of technology, it is smaller, lighter, safer and more powerful.

This article was written by Jack Keystone of Net Cables Plus (http://www.netcablesplus.com) an online store that carries a wide variety of cables and accessories. Choose from among a large selection of Ethernet, USB, fiber optic, or any type of cables and connectors your business requires. Net Cables Plus handles any size order from the single, 1-foot cable to a truckload of bulk cable.