Fiber optic sensors offer many advantages over conventional sensors, including; small size, low weight, high strength and durability. Standard silica optical fibers are limited by the material properties of silica. Temperatures above 700°C and other harsh environments are incompatible with standard optical fiber sensors. Sapphire fiber sensors offer another option for fiber optic sensing. Sapphire fibers are limited by the material properties of sapphire, which include high melting point, extreme hardness and imperviousness to chemical reactions and radiation. These properties coupled with the advantages of conventional fiber optic sensing make sapphire optical fiber sensors a good candidate for sensing requirements in harsh environments. We investigate the potential for the use of sapphire fibers as sensors. Two sensors are developed based on widely different techniques. Results from preliminary tests of each are given. / Master of Science

The objective of this thesis is to demonstrate the feasibility of developing holograms in the cladding region of an optical fiber. The cladding is first stripped and replaced with dichromated gelatin ( DCG ) which is a highly efficient holographic storage medium. The evanescent field of the fiber is used as the reference beam to form an interference pattern with an object wave. The interference of the two fields is recorded in the DCG and forms the hologram. The holograms recorded have a grating type structure and can be utilized for guiding light selectively in and out of the fiber. / Master of Science