Effect of input polarization angle on force sensitivity of embedded single-mode polarimetric sensors

Abstract

The effect of input angle of polarization on the force sensitivity of embedded single mode fibers was investigated. Two types of fiber specimens were used -- one consisted of a fiber embedded with its protective plastic coating intact while the other had a fiber stripped of this coating. Plane polarized light, whose direction could be varied, was launched into the fibers and the embedded portions were compressed. The polarization changes due to birefringence effects were recorded with a pair of polarizers and photodiodes. The experiments show that the amount of polarization change due to force varied with input polarization angle. Hence, the force sensitivity of polarimetric stress sensors depended on the input angle of the plane polarized light. It was also found that the load- induced polarization changes were more significant in the stripped specimen than in the fiber embedded with coating.