Sapphire-Derived Fibers and Optical Fiber Sensing

Abstract

The optical fiber being optical sensors exhibit several advantages including the immunity to the electromagnetic interference, simple structure, easy to carry, and large dynamic range. Especially, the possibility of working under harsh environment marks the fiber sensors that are superior to the electrical sensor counterparts. To achieve new breakthroughs in high-temperature sensing technology, exploring high-temperature-resistant optical fibers with good mechanical properties is necessary. The sapphire-derived fiber (SDF), a high-concentration alumina-doped silica fiber based on a single-crystal sapphire rod, has good mechanical strength, high-temperature resistance, etc. Such SDF shows great potential in high-temperature sensing and distributed strain sensing. This chapter mainly introduces the SDF for high-temperature sensing application. Firstly, the fabrication and the characterization of SDF have been introduced. Secondly, the SDF-based optical devices have been discussed including Fabry–Perot interferometer, Bragg grating, Mach–Zehnder interferometer, long-period fiber grating. Then, the advantages of SDF fiber in the field of high temperature are proved by introducing the performance of various sensors based on SDF.