Single Crystal Fiber Sensors for Temperature Measurements in Jet Engines

Very light sensors having a fast response time are required for making direct, non-intrusive measurements in a jet engine system environment for precise control. In order to monitor key physical parameters in this environment, it will be necessary to develop new concepts in sensor design to measure such things as temperature. Present day sensors will not operate reliably in this environment and are much too large. Fiber optic sensors offer a possible solution to this problem. Lasergenics Corportation is proposing to investigate single crystal fibers of MgAl2O4 and Y2O3 doped with neodymium for this application. These materials can withstand the harsh environment that will exist at temperatures as high as 2300 degrees Celsius. We are proposing a unique approach that would allow the measurement of temperature with a single crystal fiber optic. The temperature will be determined by measuring the flouorescence decay time as a function of temperature using the phase shift method. This concept will be tested during the Phase I effort. For the Phase II effort we will determine sensor and data transmission link design characteristics usable in this environment, fabricate a breadboard and test it in a jet engine environment. Anticipated Military Benefits/Potential Commercial Applications of the Research or Development: This program can result in a new concept for fiber optic sensors for high temperatures in harsh environments such as jet engines. Such a sensor can result in important savings in fuel, maintenance and repair costs because of more precise control. They could find application in process control in the steel, chemical, and semiconductor industries, in power generation plants, in plasma, fusion, MHD, combustion and chemical research.