The use of fiber optic technology for data communications has grown in popularity as a result of increased demand for bandwidth and a corresponding drop in the price of fiber cabling and installation. The following characteristics of fiber optic transmission make it inherently superior to communicating over copper wires:

Distance and bandwidth are determined by several factors. The most important are type of cable, type of light source, and size of cable.

Fiber type — when referring to the cable construction, there are basically two types of fiber optic cables: multimode and single mode. In multimode fiber, the relatively large size of the core allows propagation of light at various angles. As a result, this type of cable has high attenuation. In single mode fiber, the size of the core is so small that only a single transmission path exist. The single mode fiber features high bandwidth and low attenuation.

Light source — signal attenuation in fiber optic depends on wavelength. Minimal attenuation occurs in three wavelengths: 850 nm, 1300 nm and 1550 nm. The 850 nm light sources (LEDS) are the most popular, but are limited in distance. The 1300 nm LEDs are expensive to manufacture; however, they feature high bandwidth and long distances. The 1550 nm is used only in cases where very long ranges are required, as it is very expensive.

Laser diode — Laser diodes are used mainly for increased range (more optical budget) over the same fiber cables, usually over single mode fibers. The Laser diodes available are 1300 nm and 1550 nm wavelength.

Fiber size — fiber optic cable size is defined by a set of two numbers (e.g. 62.5/1 25). The first is the diameter of the core, and the second is the outer diameter of the core and cladding, both in microns. RAD products operate with all the common sizes of fiber optic cable; however, the distance may differ from type to type, and care should be taken to calculate both the fiber attenuation and the losses at connection points along the line.

The fiber optic connector is a critical component in the network and has to be chosen carefully since a slight misalignment may result in loss of power budget.

The most common types are:

SMA — this is a screw-on type connector. As it was the first standard, it was the most common in the past but is now less popular.

ST — this is a bayonet type connector. This connector is more popular since the connection it provides is more accurate and secure.

FC-PC — this type of connector is a combination of a bayonet and screw-on connector. It is not as popular as the ST but it incorporates the best qualities of the SMA and ST connectors.

SC — this quick-connect square-shaped connector is gaining more and more popularity in the market

In addition to all the advantages discussed above, RAD fiber optic products offer the following:

FOMi-40 — high speed, n x 56,64 fiber optic modem with management

FOMi-El/T1 — El/T1 fiber optic modem with management

F-TEL — fiber optic telephone adapter