Avionic embedded fiber optic links

For almost twenty-five years, the major aircraft players and their suppliers have been investigating the potential for improving aircrafts by the introduction of fiber optic technologies. And yet, in the beginning, the adoption of fiber optics was far from a done deal because of the difficulty of working with them and interconnecting them with new advanced embedded systems.

The systems inside aircrafts and helicopters require massive real-time data transfers. That means the systems require high bandwidth, interference-free physical medium. With data transmission rates currently up to 10 gigabits/second, and thanks to their immunity to electromagnetic interference [EMI], optical fibers are the perfect match to accommodate today’s bandwidth-intensive applications.

The challenge is to develop, demonstrate and integrate a lightweight but robust and reliable optical cable plant, together with fiber optic sensors and connectors, for both commercial and military aircraft and helicopter applications.

The FCXtreme® is an FC-type connector fully compatible with the FC JIS standard. It is rather short (< 31mm) and has an outer diameter smaller than 10mm. The NANOXtreme® has a unique design and is even shorter (< 6 mm). Hence, it allows very compact optical fiber links (< 36mm).

These optical connectors are easy to mount by design and are compatible with all the different types of optical fiber assemblies such as gluing, brazing, ceramic bounding, or glass soldering technologies. Besides, they can be used with all types of single-mode or multimode fibers and can accept all types of protections including metal, tube, or peek.

To meet the challenge, SEDI-ATI has designed specific fiber optic assemblies with avionics grade fiber optic cables and connectors. We mainly integrate Avioptics^® Fiber Optic Cables from our partner OFS Optics. These cables are configured to withstand exposure to corrosive and other chemicals, including jet fuel, oil, solvents, and hydrolytic liquids. Besides, we propose specific connector terminations such as OFS SMA 905 Crimp & Cleave connectors for field connectorization and repair (no epoxy, no curing, no polishing steps).

To go beyond, SEDI-ATI released in October 2018 two new versatile and compact connectors for optical fiber links dedicated to cover the demanding requirements of defense and aerospace applications. These connectors withstand shocks (1-meter x 10), vibrations (5Hz to 55Hz), harsh temperatures (from -55°C to +125°C), corrosive or radiative environments, and demonstrate very low outgassing levels since they are exclusively made of stainless steel and ceramic parts.

Today, many aircrafts and helicopters use fiber optic components.

• Commercial aircrafts: Airbus A340-600, Airbus A350-XWB, Airbus A380-800, Boeing 787,
• Military aircrafts: Airbus A400M, BAE Systems Typhoon, Boeing Lockheed Martin F-22 Lightning, LMCO F-35,
• Helicopters: AW-101 Merlin HC.3, AW-159 Wildcat, Boeing Chinook HC.3.