Fiber optic cable is a much different type of channel in the network structure. Rather than transmitting signals over copper conductors in the form of electrical voltages, fiber optic cables transmit pulses of light over a glass or plastic conductor.
Fiber optic cable is resistive to electromagnetic interference and less prone to attenuation than are copper cables. Attenuation is a signal’s propensity to weaken as it travels over a cable. With copper cables, signals weaken to the point of becoming indecipherable after 100 to 500 meters. In some cases fiber optic cables can extend distances up to 120 kilometers without significant signal weakening. Fiber optic cable is the preferred medium for installations that span long distances.
Additionally, it is more secure than copper because the fiber optic link can’t be disturbed without affecting the normal communication over that link. Fiber optic cable is found in two types: single-mode and multimode. The difference between them is identified by the thickness of the core and the cladding.
- Single-mode fiber uses a single-wavelength laser as a light source, and is able to transmit signals for significantly long distances. Single-mode fiber is commonly found in outdoor installations such as cable television networks that span great distances. This type of cable is less applicable to LAN installations because it is more costly than multimode and has a higher bend radius.
- Multimode fiber uses a light emitting diode (LED) as a light source instead of a laser and carries multiple wavelengths. As opposed to single-mode, multimode fiber cannot span great distances but it bends around corners better and is much cheaper.