Competence Center for Specialty Optical Fibers

We report on measurements of the spatially resolved characterization of flux-pinning induced strain of rectangular shaped bulk YBCO samples. The spatially resolved strain measurements are accomplished by the use 2 fiber Bragg grating arrays, which are with an included angle of 45° fixed to the surface. In this paper first attempts to confirm the shape distortions caused by the flux-pinning induced strain as predicted in [1,2] will be presented. Two sample setups, a single bulk and a “mirror” arrangement, will be ompared. This mirror setup represents a model configuration for a measurement inside the superconductor, where demagnetization effects can be neglected and the magnetic field merely has a z-component.