Page 86 - 2020 Interconnect Innovations eBook

86
Consistency: If a fiber optic system is not designed correctly, performance will suffer. Since fiber connections rely on precise alignment tolerances, there is little room for errors or discrepancies when machining and installing components for fiber optic systems.
IMAGE
» A feature-rich ARINC 801 NXTCore optical terminus from XiOptics.
Ease of Assembly: Fiber optic systems can be more complicated to install than electrical cabling systems if technicians are not properly trained and equipped. Modern connectors are designed to ease assembly by simplifying the mating, test, and repair processes, but fiber optic connectors must reliably hold and precisely align fibers to ensure low signal loss and maximize transmission speeds.
IMAGE
» An M29504/6 socket terminal kit from XiOptics.
Size: Fiber optic cable combines small size with high bandwidth capabilities. The small diameter allows fiber optic cables to run through tighter spaces, including those where conventional electric cable is not viable. As such, fiber optic cables are a practical solution for cities, where lots of underground pipes and cables already exist, and buildings where wiring is plentiful and ducts are cramped. If the installation demands a rugged cable design, tight buffering of optical fibers will provide adequate protection and ruggedness.
Weight: Cable and connector weight are a vital factor for many applications, and particularly aviation. For applications that require high data speeds and/or bandwidth, the weight-to-performance ratio for fiber optics is vastly superior to that of copper cable. The amount of copper cable required to match the performance of fiber optic is immense. Conductor weight typically scales as 1/voltage^2, so even at 400V, copper weighs over twice as much as fiber. Depending on individual application requirements, fiber optic systems can utilize ceramic, metal, or plastic ferrules. Housings are also typically metal or plastic. Plastic is the lightest, followed by ceramic and metal.
Repairability: Fiber optic cabling can be arduous to repair. One of the main causes of optical fiber failure is backhoe fade, in which the optical fiber cable is cut or damaged by digging equipment. Fiber optic cables are repaired in the same way that they are spliced. Unlike conventional copper wire, a cut fiber cable cannot simply be twisted or crimped back together. If the fiber is damaged but not cut, the bad section is removed, and the remaining fiber is carefully spliced. There are two common methods for splicing glass fiber optic cables: fusion splicing, which requires an expensive tool and proper training, and mechanical splicing, which involves the difficult task of aligning fiber cores and often results in higher-loss splices.
Cost Sensitivity: The high data speeds fiber optics deliver come at a higher component cost than traditional electrical cabling and connectors, but cost parity is near. In weight-sensitive applications such as spacecraft and aircraft, the reduced weight of optical fiber more than justifies its use. As such, most modern avionics applications use optical media. For high-speed and high-bandwidth applications, the benefits also outweigh the added costs. In addition, single-mode optical fiber often costs less than multimode fiber.