Weighted sensitivity optical fiber sensors: theory and applications

The polarimetric behavior of conventional dual mode, elliptical-core, optical fiber sensors is investigated. To compliment the experimental results, a novel linearly polarized modal analysis of elliptical-core geometries is performed. The method numerically finds solutions of a waveguide equation described by Mathieu differential equations. To move beyond conventional dual mode fiber sensing applications, selected placement of the dual mode fiber endpoints upon a flexible structure is investigated. Modal filtering behavior will result if the endpoints are chosen to span two antinodes of the underlying structure. To truly achieve signal processing capabilities, spatially weighting the sensitivity of the sensor becomes necessary. Experimental results are described and future applications are proposed.