What is an optical fiber?

What is an optical fiber?

An optical fiber (or fibre) is a glass or plastic fiber that carries light along its length. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communications. Fibers are used instead of metal wires because signals travel along them with less loss, and they are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.

Single Optical Fiber Parts:-

Parts Of Single Optical Fiber

If you look closely at a single optical fiber, you will see that it has the following parts:

1. Core - Thin glass center of the fiber where the light travels
2. Cladding - Outer optical material surrounding the core that reflects the light back into the core
3. Buffer coating - Plastic coating that protects the fiber from damage and moisture

Hundreds or thousands of these optical fibers are arranged in bundles in optical cables. The bundles are protected by the cable's outer covering, called a jacket.

Optical fibers come in two types:

1. Single-mode fibers
2. Multi-mode fibers

Single-mode fibers have small cores (about 3.5 x 10^-4 inches or 9 microns in diameter) and transmit infrared laser light (wavelength = 1,300 to 1,550 nanometers).

Multi-mode fibers have larger cores (about 2.5 x 10^-3 inches or 62.5 microns in diameter) and transmit infrared light (wavelength = 850 to 1,300 nm) from light emitting diodes (LEDs).

Some optical fibers can be made from plastic. These fibers have a large core (0.04 inches or 1 mm diameter) and transmit visible red light (wavelength = 650 nm) from LEDs.

Advantages Of FIBER OPTICS:-

1. Less expensive - Several miles of optical cable can be made cheaper than equivalent lengths of copper wire. This saves your provider (cable TV, Internet) and you money.
2. Thinner - Optical fibers can be drawn to smaller diameters than copper wire.
3. 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.
4. Less signal degradation - The loss of signal in optical fiber is less than in copper wire.
5. 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.
6. Low 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 your provider and you money.
7. Digital signals - Optical fibers are ideally suited for carrying digital information, which is especially useful in computer networks.
8. Non-flammable - Because no electricity is passed through optical fibers, there is no fire hazard.
9. Lightweight - An optical cable weighs less than a comparable copper wire cable. Fiber-optic cables take up less space in the ground.
10. 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:
1. Medical imaging - in bronchoscopes, endoscopes, laparoscopes
2. Mechanical imaging - inspecting mechanical welds in pipes and engines (in airplanes,rockets,space shuttles,cars )
11. Plumbing - to inspect sewer lines