Fiber Optic Cable and Connector Selection
By Andy Devine and Ron Deppen Connector Specifier November, 2000
Use these 11 steps as a guide to selecting fiber optic cables and connectors for high-reliability applications.
Proper selection of fiber optic cables and connectors for specific uses is growing even more important as fiber optic systems become the transmission medium of choice for communications and aircraft applications, and even antenna links. The following 11 steps guide readers through the choices that must be made in selecting fiber optic cables and connectors for high-reliability applications. This provides the knowledge to know what questions to ask and what tradeoffs are being made when designing a fiber optic system.
1. Define Environmental Requirements
While some fiber optic systems are in benign environments such as inside a building, others are strapped to rockets and blasted into space where they must work reliably for years. The environment that the system will operate in greatly affects how it is designed. The major concern in local area networks (LANs) is cost, while the major concern in space applications is reliability. These two examples are at the extremes; many systems fall in between, such as Regional Bell Operating Companies (RBOCs) systems, long-haul terrestrial and sub-sea systems, and systems in ships, airplanes and cars. Many environmental factors should be considered such as temperature extremes, humidity and vibration, as well as the loads the cable will experience during installation and operation.
2. Select Transmission Standard
As the applications for fiber optics have expanded and data rates have increased, the number of transmission standards has also increased. See Table 1 for the most common standards. Not all fiber optic systems utilize these standards. Most system decisions are driven by the current availability of the fiber optic transmitters, receivers and components that meet the environmental requirements.
3. Select System Architecture
The biggest advantage of using fiber optics is the ability to handle a large amount of data over a single piece of fiber. This reduces the amount of hardware required and, therefore, increases the reliability of the system. When designing a system, it is important to maximize the amount of insertion loss and return loss that can be tolerated to increase the reliability. System designers must also account for degradation over the life of the system, taking into account beginning- and end-of-life performance parameters.