Towards 1-component Bragg-grating based shape sensing

Shape sensing based on optical fiber-Bragg-grating technology is an important field of research that promises to bring a solution for the observation and tracking of flexible tubes. Currently for shape sensing, an optical fiber with integrated Bragg-gratings is attached to a flexible material, to measure the material strain caused by bending. In this paper, a new approach for shape sensing is presented. For the first time, the Bragg-grating structures and the optical waveguides are directly inscribed in planar cyclo-olefin copolymers that can perform characteristic deformation itself. This new method solves many present problems in shape sensing. These problems are e.g. that the placement of the fibers along the carrier material is difficult to realize in practice. Also the fiber does not always connect properly to the carrier material. Thus, the material deformation can not be sufficiently applied to the fiber. The general idea of optical shape sensing and the advantages of the new concept are explained in section I and II. Further on, the manufacturing process of a prototype is described in section II-A. To use the presented 1-component sensor for shape sensing, a geometrical model is defined and assumptions regarding the behavior of the measured values are made in section II-B. The prototype is tested and the measurement data is compared to the defined model. The obtained results are shown in section III. Finally, in section IV, a conclusion of the work is given.