Optimal coatings for intelligent structure fiber optic sensors

The importance of optical fiber coatings to the overall performance of structurally embedded optical fiber sensors is explored with closed form solutions. Particular attention is paid to the mechanical ramifications of material property and coating diameter choice when the fiber is embedded in a transversely isotropic host material. Analytical solutions are developed which show that strain concentrations near an embedded optical fiber are highly dependent on the coating material properties. Clear evidence is presented which indicates that there exist optimum coating material and radius combinations for a given host material. This optimum choice can minimize or even eliminate stress concentrations in the host material immediately surrounding the embedded fiber. Sensor phase sensitivity is explored for a wide range of coating properties.