Page 83 - Optical Communications Essentials

Optical Fiber Cables

Optical Fiber Cables 73

Figure 5.5. Duplex tight-buffered interconnect cable.

Figure 5.6. Example of an indoor six-fiber breakout
cable.

be created. For example, two of these modules can be encapsulated in an outer
PVC jacket to form a popular duplex cable, as shown in Fig. 5.5. Fiber optic
patch cords, also known as jumper cables, are short lengths (usually less than
2m) of simplex or duplex cable with connectors on both ends. They are used
to connect lightwave test equipment to a fiber patch panel or to interconnect
optical transmission modules within an equipment rack.
■ Breakout or fanout cable. Up to 12 tight-buffered fibers can be stranded
around a central strength member to form what is called a breakout or fanout
cable. Breakout cables are designed specifically for low- to medium-fiber-
count applications where it is necessary to protect individual jacketed fibers.
Figure 5.6 illustrates a six-fiber cable for local-area network applications. The
breakout cable facilitates easy installation of fiber optic connectors. All that
needs be done to prepare the ends of the cable for connector attachment is to
remove the outer jacket, thereby exposing what are essentially individual single-
fiber cables. An independent connector then can be attached to each fiber.
With such a cable configuration, breaking the individually terminated fibers
out to separate pieces of equipment can be achieved easily.
■ Distribution cable. As shown in Fig. 5.7, individual or small groupings of tight-
buffered fibers can be stranded around a nonconducting central strength
member to form what is called a distribution cable. This cable can be used for
a wide range of intrabuilding and interbuilding network applications for send-
ing data, voice, and video signals. If groupings of fibers are desired, they can
be wound around a smaller strength member and held together with a cable
wrapping tape, or they can be in a loose-tube structure. Distribution cables

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