An epoxyless single-fiber ST connector for harsh avionic environments

Avionic systems commonly route data and control signals through optical fiber cables for their high bandwidth over longer distances and their immunity to electro-magnetic interference. The current commercially-available optical connectors such as the 29504 termini use epoxy to glue the fiber within the ferrule's hole. Epoxy softens and creeps at high temperatures, and it causes substantial changes in the optical insertion loss when the fiber pistons inside the ferrule at elevated temperatures and remains upon cooling. This paper describes a novel, metallic, single-fiber ferrule in an ST-style connector for harsh avionic environments that eliminates epoxy. The ferrule is rugged since it is constructed of titanium. Due to titanium's CTE match with zirconia and the elimination of the epoxy, this ferrule shows good optical performance during temperature cycling between -55°C and 165°C per MIL-PRF-64266.