Optical fibers are long, thin strands of very pure glass about the diameter of a human hair. They are arranged in bundles called fiber optic cables and used to transmit light signals over long distances. Optical fibers are made up of two concentric cylindrical glasses. The inner core is surrounded by a concentric core made up of glass and of lower refractive index known as cladding. Protective layer with which the cladding is surrounded is called as protective sheath. The total internal reflection takes place at the cladding – core interface. The core diameter ranges in a few microns and is not much larger than the wavelength of light used. When high data transmission rates are not required, core with comparatively large diameters are used which may be of a few hundred microns.
- Cheap - 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.
- Thinner - Optical fibers can be drawn to smaller diameters than copper wire.
- 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.
- Less signal degradation – The loss of signal in optical fiber is less than in copper wire.
- 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.
- Lightweight – An optical cable weighs less than a comparable copper wire cable. Fiber optic cable take up less space in the ground.
- Long Life: Optical fibers usually live long for about more than 100 years.
- Limited Application: Can only be used on ground, but cannot leave the ground or be associated with the mobile communication.
- Nuclear Radiations: On exposure to the nuclear radiations the glass darken and the harder the glass is easily it’ll lose its color.
- Low Power: Light emitting sources are limited to low power and tough high power emitters are available but are costly.
- Fragility : The optical fibers are easily broken.
- Distance: The distance between the transmitter and receiver must be short or if it is long signal repeaters are used to ensure the signals are not weak.