How Fiber Optics Work

By: Craig Freudenrich, Ph.D. & Chris Pollette  | 

Advantages of Fiber Optics

Why are fiber-optic systems revolutionizing telecommunications? Compared to conventional metal wire (copper wire), optical fibers:

Are less expensive. Fiber-optic cable is more expensive than copper wire, but it also requires less maintenance. In the long run it saves you and your internet provider money.


Are thinner. Optical fibers can be drawn to smaller diameters than copper wire.

Have higher carrying capacity. Because optical fibers are thinner than copper wires, more fibers can be bundled into a given-diameter cable than copper wires. This allows more phone lines to go over the same cable or more channels to come through the cable into your cable TV box.

Have less signal degradation. The loss of signal in optical fiber is less than in copper wire.

Have no interference from light signals. Unlike electrical signals in copper wires, light signals from one fiber do not interfere with those of other fibers in the same cable. This means clearer phone conversations or TV reception.

Have lower power. Because signals in optical fibers degrade less, lower-power transmitters can be used instead of the high-voltage electrical transmitters needed for copper wires. Again, this saves you and your provider money.

Have digital signals. Optical fibers are ideally suited for carrying digital information, which is especially useful in computer networks.

Are non-flammable. Because no electricity is passed through optical fibers, it does not create heat, reducing the risk of fire.

Are lightweight. An optical cable weighs less than a comparable copper-wire cable (4 pounds or 2 kilograms per 1,000 feet or 305 meters, versus 39 pounds or 18 kilograms per 1,000 feet). Fiber-optic cables take up less space in the ground, too.

Are flexible. Because fiber optics are so flexible and can transmit and receive light, they are used in many flexible digital cameras for the following purposes:

  • medical imaging - in bronchoscopes, endoscopes, laparoscopes
  • mechanical imaging - inspecting mechanical welds in pipes and engines (in airplanes, rockets, space shuttles, cars)
  • plumbing - to inspect sewer lines

Because of these advantages, you see fiber optics in many industries, most notably telecommunications and computer networks. For example, if you phoned Europe on a landline from the United States (or vice versa) and the signal bounces off a communications satellite, you'd often hear an echo on the line. But with transatlantic fiber-optic cables, you have a direct connection with no echoes.