High resolution optical time domain reflectometry and its applications

High resolution Optical Time Domain Reflectometry (OTDR) measurements have recently allowed spatial resolutions of less than one millimeter. These capabilities indicate that OTDR techniques may be suitable for non-conventional applications such as the determination of fiber strain. This thesis presents an investigation of how high resolution OTDR techniques can be used in such applications. The concept of fiber segmentation via partially reflective optical splices for local strain measurements is discussed both from a theoretical and practical standpoint. Experimental results demonstrating the feasibility of such local strain measurements are also given. Another part of this investigation considers the practical details of the proposed strain measurement technique, addressing such topics as launching conditions, and environmental factors. Possible applications of the local strain measurement techniques, such as two- and three-dimensional stress analysis, and strain determination of fiber optic cables, are also presented. These applications also include the development of small, easy to manufacture elastomeric optical splices, which were shown to yield acceptable performance < 0.2 dB losses) for multimode fibers.