Single-crystal sapphire fiber-based strain sensor for high-temperature applications

Single-crystal sapphire fibers have a very high melting point (up to 2050degreesC), which renders them a very good candidate for the. sensing applications at a very high temperature. We present in this paper the recent work of developing single-crystal sapphire fiber extrinsic Fabry-Wrot interferometric strain sensors based on the whitelight interferometric spectrum demodulation technique. Prototype sapphire strain sensors were fabricated and tested at high temperatures up to 1004degreesC. The preliminary experimental results indicate that the sensors are promising to be used under high-temperature environments for making strain measurements with the strain measurement resolution of 0.2-mu strain.