High-Temperature-Resistant Fiber Optic Grating Based Aerospace Sensors

Fiber optic gratings are critical components for advanced multi-point sensor systems as well as a multitude of photonic circuitry applications. Standard industrial laser-written gratings, however, start to permanently degrade at temperatures well below the melting point of glass, and they thus lose their sensing capability in thermally harsh environments. Intelligent Fiber Optic Systems Corporation (IFOS) is proposing a fabrication method to significantly extend the range of operation of reliable grating-based sensors and components to temperatures close to the melting point of glass. Phase I demonstrated highly repeatable operation for unpackaged/uncoated sensors to well over 800°C with potential for survivability to well over 1000°C. The Phase II challenge will be to take the sensors from the laboratory prototype stage to packaged sensor prototypes suitable for aerospace field use. IFOS will optimize a fabrication system for robust heat-resistant grating-based sensors, and design a complete sensor system to establish accurate and reliable strain measurement with survivability and operation at extremely high temperatures. The system will include a compact interrogator allowing for remote measurement in harsh and hostile environments with readout from strain sensor gratings accomplished at extremely high speed and high resolution using secure fiber optic links.