TY - JOUR A1 - Kasinathan, M. A1 - Wosniok, Aleksander A1 - Krebber, Katerina A1 - Babu Rao, C. T1 - Optical fiber defect detection using Brillouin optical time domain analyser JF - Indian Journal of Pure & Applied Physics N2 - A new technique for optical fiber defect detection using Brillouin distributed fiber optic sensor (DFOS) has been proposed and experimentally demonstrated in this paper. This technique is based on stimulated Brillouin scattering (SBS), which offers three wave interaction in single mode optical fiber (SMF -10 μm/125 μm acrylic coated fiber). The nonlinear effect of SBS is manipulated to locate the defect in optical fiber using distributed sensing technology. Various kind of defects may be present in optical fibers. This paper details a case study on observation of a defect, which manifests its presence in certain temperature values. The detail of defect detection through distributed fiber sensor using the SBS has been brought out. SBS is sensitive to temperature and strain. In order to study the effect of defect in distributed fiber sensor as function of temperature and strain, the distributed pre-strained and unstrained optical fiber is subjected to temperature variation and corresponding measurements are obtained with Brillouin optical time domain analyser (BOTDA). This technique enables the utilization of Brillouin parameters, such as decreased amplitude, frequency and increased linewidth in the defect region of the fiber length. The fiber defect location can be determined with spatial resolution accuracy of less than 50 cm of using BOTDA technique. KW - Stimulated Brillouin scattering KW - Distributed sensor KW - Optical fiber KW - Brillouin Optical Time Domain Analysis PY - 2016 SN - 0019-5596 VL - 54 IS - 9 SP - 565 EP - 570 PB - NISCAIR AN - OPUS4-37914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kasinathan, M. A1 - Babu Rao, C. A1 - Murali, N. A1 - Jayakumar, T. A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Bond monitoring in temperature dependent applications using Brillouin optical time domain analyser JF - Journal of Optics N2 - Adhesive bond has to be evaluated for its integrity over a range of temperature. Adhesive is being used to bond the sensors with structures. There is no validated technique to test its performance. In this paper, we propose a Brillouin Optical Time Domain Analyzer (BOTDA) based methodology to detect temperature-induced adhesive bond failure below room temperature using distributed fiber optic sensor. The differential coefficient of thermal expansion of the structure and fiber sensor can lead to bond failure at low temperature. Optical fiber impregnated in the structure will experience differential temperature/strain due to debond of the adhesive. This leads to the frequency and amplitude decomposition of the Brillouin spectra. This is a good indication for real-time monitoring of the integrity of a bond. KW - Adhesive bond KW - Brillouin scattering KW - optical fiber sensor KW - Brillouin optical time domain analysis KW - distributed sensor PY - 2016 DO - https://doi.org/10.1007/s12596-015-0266-5 VL - 45 IS - 1 SP - 44 EP - 49 PB - Springer AN - OPUS4-37923 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -