Hollow core photonic crystal fibers for temperature measurement in hydrogen combustors

The temperature in hydrogen combustor turbines must be monitored in a non-intrusive way in order to prevent expensive damage from flashback and thermoacoustic instabilities. We propose and analyze a novel method of temperature detection based on hollow core photonic crystal fibers. It exploits the measurement of the thermal vibrations of a microsphere that is optically trapped inside the fiber. This configuration realizes an optical probe allowing to determine remotely the temperature at a chosen point within the turbine. An optical force model is employed to predict the characteristics of our approach. The system allows a tunable temperature sensitivity, dependent on pressure inside the fiber, to be obtained together with high spatial resolution.