TY - JOUR A1 - Liehr, Sascha A1 - Münzenberger, Sven A1 - Krebber, Katerina T1 - Wavelength-scanning coherent OTDR for dynamic high strain resolution sensing JF - Optics Express N2 - Distributed vibration sensing in optical fibers opened entirely new opportunities and penetrated various sectors from security to seismic monitoring. Here, we demonstrate a most simple and robust approach for dynamic strain measurement using wavelength-scanning coherent optical time domain reflectometry (C-OTDR). Our method is based on laser current modulation and Rayleigh backscatter shift correlation. As opposed to common single-wavelength phase demodulation techniques, also the algebraic sign of the strain change is retrieved. This is crucial for the intended applications in structural health monitoring and modal analysis. A linear strain response down to 47.5 pε and strain noise of 100 pε/√Hz is demonstrated for repetition rates in the kHz range. A field application of a vibrating bridge is presented. Our approach provides a cost-effective high-resolution method for structural vibration analysis and geophysical applications. KW - Fiber optics sensors KW - Optical time domain reflectometry KW - Rayleigh Scattering KW - Distributed acoustic sensing KW - Distributed strain sensing PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-448069 DO - https://doi.org/10.1364/OE.26.010573 SN - 1094-4087 VL - 26 IS - 8 SP - 10573 EP - 10588 PB - Optical Society of America AN - OPUS4-44806 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -