Fiber optic cables get all the praise when it comes to new data transmission technology, but their efficiency greatly relies on a few small power connector components— cable connectors. The size and versatility of a fiber connector allows fiber optic cabling to transmit data across distributed avionics and eliminate the need for additional signal support equipment.
Fiber optic connectors hold individual fibers in place. They incorporate an associated adapter for alignment and mating of fiber ends which forms a unified connection point. Another way to think of this device is as a plug with a protruding ferrule. A ferrule protects the mating ends of a fiber from degradation, as splitting or cracking will damage the fiber’s ability to reflect light effectively.
While airlines formerly had to rely on an avionics bay to route data through the aircraft, the compact size of the fiber optic optical connector allows distributed avionics to put processing power closer to its point of use. Most aircraft formerly utilized copper cables, which require additional equipment for signal support, adding to overall weight. As a result, fiber optic cables offer 25% in space savings and 50% overall weight reduction. Connectors with composite shells are 40% lighter than metal connectors.
Along with knowing the benefits of connectors, you’ll want to know about the most common connectors that you might come across in aviation. Common 2.5 mm connectors, small form factor connectors, and multi-fiber push on connectors are the most prevalent fiber connectors used within the aviation industry. A general rule for this category of connectors is the following: common 2.5 mm connectors are the most versatile, small form factor(SFF) connectors are intended for high density purposes, and multi-fiber push ons (MPO) support high-data environments.
There are three types of 2.5 mm common connectors, square connectors (SC), firewire connectors (FC), and stainless-steel connectors (ST). As their name suggests, common 2.5 mm connectors have a 2.5 mm ferrule size and therefore can be used interchangeably, or mixed and matched with the addition of a hybrid adapter. These connectors were commonly used in the 1980’s and 1990’s, but the SC connector is still commonly seen in application with fiber optics.
SFF connectors have a latch design that allows for strong connections with reduced signal loss. In addition, it has a 1.25 mm ferrule giving it a compact and reliable design. The low loss connector (LC), a variety of SFF, is one of the most successful connectors in the industry.
To round out our connectors, the most commonly used power connector component in aviation is the MPO. With the rapid advancement of avionic technology, these connectors are necessary to provide high speed data transfer end-to-end. This connector can contain a multitude of fibers and can incorporate multimode fibers as well. MPO connectors are specified as “male” on one end and “female” on the other to ensure that all fibers are properly aligned.