TY - CONF A1 - Liehr, Sascha A1 - Burgmeier, J. A1 - Krebber, Katerina T1 - Quasi-distributed fiber bend and temperature measurement in femtosecond laser-structured POF N2 - We propose to use focused femtosecond laser pulses to inscribe Scattering damage in the core of polymer optical fibers for interrogation as quasi-distributed sensor points by optical time domain reflectometry. Fiber bend measurement is demonstrated on off-center inscribed sensor points and absolute temperature measurement is presented by evaluation of the constant backscatter intensities from the inscribed structures relative to temperature-dependent Rayleigh Scattering. Application possibilities and limitations of this new approach are discussed. T2 - POF 2013 - 22nd International conference on plastic optical fibers CY - Búzios, Rio de Janeiro, Brazil DA - 11.09.2013 KW - POF KW - Polymer optical fiber KW - Femtosecond laser KW - Optical fiber sensors KW - OTDR KW - Backscatter measurement PY - 2013 SP - 279 EP - 284 CY - Rio de Janeiro, Brazil AN - OPUS4-30082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, N. A1 - Gili, O. A1 - Liehr, Sascha A1 - Lenke, P. ED - Ilki, A. ED - Motavalli, M. ED - Goksu, C. ED - Havranek, B. T1 - Frequency domain-based distributed and dynamic optical fiber sensing in geotechnical and industrial monitoring N2 - This article reports on recent advancements in the field of distributed optical fiber sensing with a focus on the monitoring of geotechnical structures and buildings. While the classical time-domain approach to distributed sensing is widely known, this article provides an introduction into the frequency-domain analysis technique for both distributed Brillouin measurements (as commonly used for strain and temperature monitoring) and for linear backscattering measurements. The article also addresses an issue which arises when truly distributed measurements are compared among each other; a new approach to calculate differential curves from a measurement and a base-line which avoids misleading large amplitudes at physical events with strong gradients is proposed. Finally, a field test of a new read-out technology, the OFDR (optical frequency domain reflectometry) technique providing dynamic readings of length changes between discrete fiber positions, is presented. T2 - SMAR 2013 - 2nd Conference on smart monitoring, assessment and rehabilitation of civil structures CY - Istanbul, Turkey DA - 09.09.2013 PY - 2013 SN - 978-3-033-04055-7 SP - 1 EP - 8 CY - Istanbul, Turkey AN - OPUS4-30122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steffen, Milan A1 - Liehr, Sascha A1 - Basedau, Frank A1 - Krebber, Katerina ED - López-Higuera, J.M. ED - Jones, J. ED - López-Amo, M. ED - Santos, J.L. T1 - Simultaneous vibration and quasi-distributed strain measurement using incoherent OFDR and extrinsic Fabry-Perot interferometers N2 - We present a measurement setup for combined quasi-distributed strain and dynamic point-wise vibration measurement using an incoherent optical frequency domain reflectometry (I-OFDR) setup in combination with extrinsic Fabry-Perot interferometers (EFPIs). Several EFPIs can be multiplexed and at the same time the strain along their supply fibres can be measured in a quasi-distributed manner. The setup is characterised and a demonstration of its general performance is given. T2 - OFS2014 - 23rd International conference on optical fibre sensors CY - Santander, Spain DA - 02.06.2014 KW - Optical fibre sensor KW - EFPI KW - I-OFDR KW - Quasi-distributed KW - Strain KW - Dynamic length and power management PY - 2014 DO - https://doi.org/10.1117/12.2059616 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 9157 SP - 91576S-1 EP - 91576S-4 AN - OPUS4-31039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Münzenberger, Sven A1 - Borchardt, Christopher T1 - Long-distance fiber optic vibration sensing using convolutional neural networks as real-time denoisers N2 - A long distance range over tens of kilometers is a prerequisite for a wide range of distributed fiber optic vibration sensing applications. We significantly extend the attenuation-limited distance range by making use of the multidimensionality of distributed Rayleigh backscatter data: Using the wavelength-scanning coherent optical time domain reflectometry (WS-COTDR) technique, backscatter data is measured along the distance and optical frequency dimensions. In this work, we develop, train, and test deep convolutional neural networks (CNNs) for fast denoising of these two-dimensional backscattering results. The very compact and efficient CNN denoiser “DnOTDR” outperforms state-of-the-art image denoising algorithms for this task and enables denoising data rates of 1.2 GB/s in real time. We demonstrate that, using the CNN denoiser, the quantitative strain measurement with nm/m resolution can be conducted with up to 100 km distance without the use of backscatter-enhanced fibers or distributed Raman or Brillouin amplification. KW - Neural networks KW - Fiber optic KW - Vibration sensing PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518694 DO - https://doi.org/10.1364/OE.402789 VL - 28 IS - 26 SP - 39325 AN - OPUS4-51869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Bauwerksüberwachung mittels faseroptischer Sensoren N2 - Dieser Vortrag umfasst eine Einführung in die faseroptische Sensorik sowie Anwendungsbeispiele in der Bauwerksüberwachung. Nach der Einteilung faseroptischer Sensorverfahren und Messprinzipien werden die grundlegenden physikalischen Effekte der verteilten faseroptischen Sensorik eingeführt. Aktuelle Anwendungsfelder in der Infrastruktur- und Bauwerksüberwachung mit dem Schwerpunkt optische Polymerfasern zur Messung hoher Dehnwerte werden präsentiert. T2 - Seminar "Zerstörungsfreie Prüfung" der TU München CY - Technische Universität München, Germany DA - 17.11.2016 KW - Faseroptische Sensorik KW - Verteilte Messverfahren KW - Dehnungsmessung KW - Temperaturmessung KW - Bauwerksüberwachung PY - 2016 AN - OPUS4-38506 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Distributed fiber optic sensing techniques: from high strain applications to nanostrain sensitivity N2 - Various applications examples for distributed high-strain measurement using polymer optical fibres and high-resolution sensing using coherent optical time domain reflectometry are summarized for structural monitoring applications. T2 - 6th International Forum on Opto-electronic Sensor-based Monitoring in Geo-engineering (FOSMG) CY - Nanjing, China DA - 03.11.2017 KW - Optical fibre sensor KW - Distributed sensing KW - Strain sensing KW - OTDR KW - Polymer optical fiber PY - 2017 AN - OPUS4-42965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schreier, Andy A1 - Wosniok, Aleksander A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Humidity-induced Brillouin frequency shift in perfluorinated polymer optical fibers N2 - We report, to our knowledge, for the first time on humidity-induced Brillouin frequency shifts in perfluorinated graded index polymer optical fibers. A linear relation between Brillouin frequency shift and humidity was observed. Furthermore, the humidity coefficient of the Brillouin frequency shift is demonstrated to be a function of temperature (-107 to -64 kHz/%r.h. or -426 to -49 kHz m3/g in the range of 20 to 60 °C). An analytical description proves temperature and humidity as two mutually independent effects on the Brillouin frequency shift. KW - Brillouin KW - Polymer optical fibre KW - Humidity PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-457165 DO - https://doi.org/10.1364/OE.26.022307 SN - 1094-4087 VL - 26 IS - 17 SP - 22307 EP - 22314 PB - Optical Society of America AN - OPUS4-45716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Muanenda, Y. A1 - Münzenberger, Sven A1 - Krebber, Katerina T1 - Wavelength-modulated C-OTDR techniques for distributed dynamic measurement N2 - We present two wavelength-modulated coherent optical time domain reflectometry techniques for dynamic, quantitative and distributed measurement. The robust and simple techniques are based on backscattering correlations along the time axis and along the pulse wavelength shift axis. T2 - 26th International Conference on Optical Fibre Sensors OFS-26 CY - Lausanne, Switzerland DA - 24.09.2018 KW - Fiber optics sensors KW - Optical time domain reflectometry KW - OTDR KW - DAS KW - Distributed strain sensor KW - Rayleigh scattering PY - 2018 DO - https://doi.org/10.1364/OFS.2018.TuE15 SP - 1 EP - 4 AN - OPUS4-46414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Wavelength-modulated C-OTDR techniques for distributed dynamic measurement N2 - We present two wavelength-modulated coherent optical time domain reflectometry techniques for dynamic, quantitative and distributed measurement. The robust and simple techniques are based on backscattering correlations along the time axis and along the pulse wavelength shift axis. T2 - 26th International Conference on Optical Fibre Sensors OFS-26 CY - Lausanne, Swiss DA - 24.09.2018 KW - Fiber optics sensors KW - Optical time domain reflectometry KW - Rayleigh scattering KW - Distributed strain sensor KW - Distributed vibration sensor KW - DAS PY - 2018 AN - OPUS4-46392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Münzenberger, Sven A1 - Krebber, Katerina T1 - Wavelength-scanning coherent OTDR for dynamic high strain resolution sensing 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 - TY - CHAP A1 - Liehr, Sascha ED - Peng, G.D. T1 - Polymer fiber sensors for structural and civil engineering applications N2 - This chapter gives an overview about polymer optical fiber (POF) sensors with the focus on structural and civil engineering applications. POF properties such as the high-strain range, the low Young’s modulus, and specific scattering effects open new fields for fiber-optic sensing applications. POF properties, sensitivities, and cross-sensitivities that are relevant for sensing are introduced. Advantages and limitations are discussed. State-of-the-art POF sensors and application examples are presented in subsections with regard to their underlying measurement principles. KW - Optical fiber sensors KW - Polymer optical fibers (POF) KW - Structural health monitoring KW - Distributed sensor PY - 2018 UR - https://link.springer.com/referenceworkentry/10.1007%2F978-981-10-1477-2_3-1 SN - 978-981-10-1477-2 DO - https://doi.org/10.1007/978-981-10-1477-2_3-1 SP - 1 EP - 36 PB - Springer Nature CY - Singapore AN - OPUS4-45754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schreier, Andy A1 - Liehr, Sascha A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Investigation on the influence of humidity on stimulated Brillouin backscattering in perfluorinated polymer optical fibers N2 - In this paper perfluorinated graded-index polymer optical fibers are characterized with respect to the influence of relative humidity changes on spectral transmission absorption and Rayleigh backscattering. The hygroscopic and thermal expansion coefficient of the fiber are determined to be CHE = (7.4 +/- 0.1) 10^-6 %r.h.^-1 and CTE = (22.7 +/- 0.3) 10^-6 K^-1, respectively. The influence of humidity on the Brillouin backscattering power and linewidth are presented for the first time to our knowledge. The Brillouin backscattering power at a pump wavelength of 1319 nm is affected by temperature and humidity. The Brillouin linewidth is observed to be a function of temperature but not of humidity. The strain coefficient of the BFS is determined to be CS = (146.5 +/- 0.9) MHz/% for a wavelength of 1319 nm within a strain range from 0.1 % to 1.5 %. The obtained results demonstrate that the humidity-induced Brillouin frequency shift is predominantly caused by the swelling of the fiber over-cladding that leads to fiber straining. KW - Brillouin KW - Polymer optical fibre KW - Humidity PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-465932 DO - https://doi.org/10.3390/s18113952 SN - 1424-8220 VL - 18 IS - 11 SP - 3952, 1 EP - 12 PB - MDPI CY - Basel, Switzerland AN - OPUS4-46593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Distributed Sensing Using POF and Application in Civil Engineering T2 - COST TD1001 European Workshop on Fibre Optic Sensors for Industrial Applications CY - Toulouse, France DA - 30.09.2014 PY - 2014 AN - OPUS4-32617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Nöther, N. A1 - Steffen, Milan A1 - Gili, O. A1 - Krebber, Katerina ED - López-Higuera, J.M. ED - Jones, J. ED - López-Amo, M. ED - Santos, J.L. T1 - Performance of digital incoherent OFDR and prospects for optical fiber sensing applications N2 - We propose a digital implementation of the incoherent optical frequency domain reflectometry (I-OFDR) technique for precise backscatter measurement and optical fiber sensing applications. Specific performance parameters of the I-OFDR are discussed and compared to an analog vector network analyzer-based I-OFDR system. Improved sensitivity, dynamic range and signal stability of the digital I-OFDR is presented and demonstrated by means of quasi-distributed length change measurement. T2 - OFS2014 - 23rd International conference on optical fibre sensors CY - Santander, Spain DA - 02.06.2014 KW - Optical fiber sensors KW - Backscatter measurement KW - Strain sensor KW - OFDR KW - OTDR PY - 2014 DO - https://doi.org/10.1117/12.2059639 SN - 0277-786X SN - 1996-756X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 9157 SP - 915737-1 EP - 915737-4 AN - OPUS4-30899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Performance of digital incoherent OFDR and prospects for optical fiber sensing applications T2 - 23rd International Conference on Optical Fiber Sensors OFS23 CY - Santander, Spain DA - 2014-06-02 PY - 2014 AN - OPUS4-30895 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Muanenda, Y. S. A1 - Münzenberger, Sven A1 - Krebber, Katerina T1 - Relative change measurement of physical quantities using dual-wavelength coherent OTDR N2 - We propose the use of alternating pulse wavelengths in a direct-detection coherent optical time domain reflectometry (C-OTDR) setup not only to measure strain and temperature changes but also to determine the correct algebraic sign of the change. The sign information is essential for the intended use in distributed mode shape analysis of civil engineering structures. Correlating relative backscatter signal shifts in the temporal/signal domain allows for measuring with correct magnitude and sign. This novel approach is simulated, experimentally implemented and demonstrated for temperature change measurement at a spatial resolution of 1 m. KW - Fiber optics sensors KW - Backscattering KW - Rayleigh KW - C-OTDR KW - Distributed sensing KW - Temperature measurement KW - Strain measurement PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-389449 DO - https://doi.org/10.1364/OE.25.000720 SN - 1094-4087 VL - 25 IS - 2 SP - 720 EP - 729 PB - Optical Society of America CY - Washington, DC, USA AN - OPUS4-38944 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Distributed strain and temperature change detection using optical frequency domain reflectometry N2 - We propose the optical frequency Domain reflectometry (OFDR) technique based on intensity modulation frequency sweep measurement for coherent distributed sensing applications. By evaluating interferometric Rayleigh scattering changes along the fibre, strain and temperature changes can be detected with a sensitivity in the ne-range and 10 mK temperature resolution. Low Vibration frequencies and vibrations up to the kHz-range can be detected by differential power change evaluation in the spatial domain. This OFDR approach is a low-cost alternative to distributed vibration sensing based on C-OTDR up to distances of several kilometres. T2 - EAGE/DGG Workshop on Fibre Optics Technology in Geophysics CY - Potsdam, Germany DA - 31.03.2017 KW - Optical fiber sensor KW - Distributed sensing KW - Interferometer KW - Strain sensing KW - Temperature sensing PY - 2017 AN - OPUS4-39864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Liehr, Sascha T1 - Health monitoring of geotechnical structures by distributed fiber optic sensors N2 - Health monitoring of ground movement via highly sensitive fiber optic sensors allows operators to detect early potential or ongoing failures in critical geotechnical structures. Particularly, the fiber optic sensors can be embedded in geosynthetics which are nowadays widely used in many geotechnical applications including earth dikes, railway embankments, landfill liners, quarries and mines. Thereby, such smart geosynthetics can be used for reinforcement, layer separation, filtration or drainage while the embedded fiber optic sensors provide information about the condition of the geotechnical structures in real time. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. The presented measurement methods for long-term monitoring are based on Brillouin scattering in silica glass optical fibers (GOFs) and optical time domain reflectometry (OTDR) in polymer optical fibers (POFs). T2 - AMA Conferences 2017 Sensor 2017 CY - Nürnberg, Germany DA - 30.05.2017 KW - Fiber optic sensor KW - Distributed sensor KW - Smart geosynthetics KW - Brillouin sensor KW - OTDR PY - 2017 SN - 978-3-9816876-4-4 DO - https://doi.org/10.5162/sensor2017/B7.4 SP - 280 EP - 285 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-40514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Phase-OFDR for Distributed Disturbance Measurement N2 - We introduce the optical frequency domain reflectometry (OFDR) technique based on intensity modulation frequency sweep measurement for distributed disturbance measurement in optical fibres. By evaluating interferometric Rayleigh scattering changes along the fibre, strain and temperature changes are detected with 100 nε sensitivity and 10 mK resolution. The vibration frequencies for low frequencies and up to the kHz-range can be obtained from power change Evaluation in the spatial domain. This novel OFDR approach is a low-cost alternative for distributed disturbance measurement up to distances of several kilometres. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - Temperature sensing KW - OFDR KW - Distributed sensor KW - Rayleigh scattering KW - Strain measurement PY - 2016 UR - http://proceedings.spiedigitallibrary.org/conferenceproceedings.aspx DO - https://doi.org/doi:10.1117/12.2236851 SN - 0277-786X VL - Vol. 9916 SP - Paper 991624, 4 PB - SPIE CY - Bellingham, Washington USA AN - OPUS4-37228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Phase-OFDR for distributed disturbance measurement N2 - We introduce the optical frequency domain reflectometry (OFDR) technique based on intensity modulation frequency sweep measurement for distributed disturbance measurement in optical fibres. By evaluating interferometric Rayleigh scattering changes along the fibre, strain and temperature changes are detected with 100 n(epsilon) sensitivity and 10 mK resolution. The vibration frequencies for low frequencies and up to the kHz-range can be obtained from power change evaluation in the spatial domain. This novel OFDR approach is a low-cost alternative for distributed disturbance measurement up to distances of several kilometres. T2 - Sixth European Workshop on Optical Fibre Sensors CY - Limerick, Ireland DA - 31.05.2016 KW - Temperature sensing KW - OFDR KW - Distributed sensor KW - Rayleigh scattering KW - Strain measurement PY - 2016 UR - http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2525146 DO - https://doi.org/doi:10.1117/12.2236851 AN - OPUS4-37229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Applications and prospects for distributed sensing using polymer optical fibres N2 - One of the unique advantages of polymer optical fibres (POF) is that they can be used to measure very high strain values up to 100 % and beyond exceeding the strain limits of silica fibre-based sensor principles. In this paper the distributed strain measurement capabilities of POF based on backscatter change evaluation are summarized and distributed backscatter measurement technologies are intro-duced. Application examples in the structural health monitoring (SHM) field are presented: a promising approach is the integration into technical textiles for high-strain measurement in earthwork structures and crack detection in buildings. The potential of POF for future applications in SHM such as distributed relative humidity sensing is discussed. T2 - International Conference on Smart Infrastructure and Construction CY - Cambridge, UK DA - 27.06.2016 KW - Strain measurement KW - Structural health monitoring KW - OTDR KW - Polymer Optical Fibre KW - Distributed sensing PY - 2016 UR - http://www.icevirtuallibrary.com/doi/abs/10.1680/tfitsi.61279.093 SN - 978-0-7277-6127-9 DO - https://doi.org/10.1680/tfi tsi.61279.093 SP - 93 EP - 98 PB - ICE Publishing CY - London, UK AN - OPUS4-37230 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Applications and prospects for distributed sensing using polymer optical fibres N2 - One of the unique advantages of polymer optical fibres (POF) is that they can be used to measure very high strain values up to 100 % and beyond exceeding the strain limits of silica fibre-based sensor principles. In this paper the distributed strain measurement capabilities of POF based on backscatter change evaluation are summarized and distributed backscatter measurement technologies are intro-duced. Application examples in the structural health monitoring (SHM) field are presented: a promising approach is the integration into technical textiles for high-strain measurement in earthwork structures and crack detection in buildings. The potential of POF for future applications in SHM such as distributed relative humidity sensing is discussed. T2 - International Conference on Smart Infrastructure and Construction CY - Cambridge, UK DA - 27.06.2016 KW - Strain measurement KW - Structural health monitoring KW - OTDR KW - Polymer Optical Fibre KW - Distributed sensing PY - 2016 UR - http://www.icevirtuallibrary.com/doi/abs/10.1680/tfitsi.61279.093 DO - https://doi.org/10.1680/tfitsi.61279.093 AN - OPUS4-37231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Steffen, Milan A1 - Wosniok, Aleksander T1 - Fördermaßnahme KMU-innovativ: Informations- und Kommunikationstechnologie (IKT), EMS-261-003 (Digital OFDR - Entwicklung der digitalen Frequenzbereichsanalyse zur verteilten Rückstreumessung in optischen Fasern-Teilvorhaben: Sensorverfahren und Systembetrachtung / Schlussbericht zum Teilvorhaben KW - Digital OFDR KW - Verteilte Rückstreumessung KW - Frequenzbereichsanalyse PY - 2015 IS - BAM Vh 8158 SP - 1 EP - 45 CY - Berlin AN - OPUS4-34170 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Gabino, L. A1 - Krywult, L. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - Distributed polymer optical fiber sensors in geotextiles for monitoring of earthwork structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Distributed sensor KW - Optical fiber sensor KW - Geotextile KW - Technical textile KW - POF sensor KW - Structural health monitoring KW - SHM KW - OTDR KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - Strain sensor PY - 2009 SN - 978-3-905594-52-2 IS - Paper 520 SP - 1 EP - 7(?) CY - Zurich, Switzerland AN - OPUS4-19787 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Münich, J.C. A1 - Stempniewski, L. A1 - Metschies, H. ED - Bernadette Havranek, ED - Masoud Motavalli, ED - Urs Meier, T1 - Distributed polymer optical fiber sensors integrated in technical textiles for monitoring of masonry structures T2 - 4th International conference on structural health monitoring of intelligent infrastructure CY - Zurich, Switzerland DA - 2009-07-22 KW - Structural health monitoring KW - Fiber optic sensors KW - OTDR KW - Polymer optical fibers (POF) KW - POF sensors KW - Distributed sensor KW - Strain sensor KW - Technical textiles KW - Masonry PY - 2009 SN - 978-3-905594-52-2 IS - Paper 521 SP - 1 EP - 7(?) CY - Zurich, Switzerland AN - OPUS4-19788 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Liehr, Sascha A1 - Lenke, Peter A1 - Wendt, Mario T1 - Distributed POF sensors for structural health monitoring - First practical applications and field tests results N2 - Distributed POF sensors based on OTDR have been developed for SHM purposes of geotechnical and masonry structures. The first field tests conducted at a creeping slope and a brick building have proved the functionality of the sensors. T2 - POF 2009 - 18th International conference on plastic optical fibers CY - Sydney, Australia DA - 2009-09-07 PY - 2009 IS - Session 1 (S1_25) SP - 1 EP - 6 CY - Sydney, Australia AN - OPUS4-19914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina ED - Fu-Kuo Chang, T1 - POF sensors integrated in technical textiles for monitoring of earthwork structures and masonry T2 - Structural health monitoring 2009 - 7th International workshop on structural health monitoring CY - Stanford, CA, USA DA - 2009-09-09 KW - Distributed strain sensor KW - Optical fiber sensor KW - Geotextile KW - Technical textiles KW - POF sensor KW - Structural health monitoring KW - SHM KW - OTDR PY - 2009 SN - 978-1-60595-007-5 VL - 2 SP - 1739 EP - 1746 PB - DEStech Publications, Inc. AN - OPUS4-19960 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Krebber, Katerina T1 - Incoherent optical frequency domain reflectometry and distributed strain detection in polymer optical fibers N2 - We present, to our knowledge for the first time, the possibility of measuring the backscatter signal of perfluorinated polymer optical fibers (POF) using an incoherent optical frequency domain reflectometry (OFDR) technique. The OFDR setup is described and it is shown that the dynamic range and measurement speed are superior to standard OTDR systems. It is shown for the first time that distributed detection of strain in POF is possible using the OFDR technique. KW - Optical frequency domain reflectometry KW - OFDR KW - OTdr KW - Polymer optical fibers KW - POF KW - Fiber sensors KW - Distributed sensors KW - Strain sensors PY - 2010 DO - https://doi.org/10.1088/0957-0233/21/1/017001 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 1 SP - 017001-1 - 017001-4 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-21625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A novel technique for quasi-distributed and dynamic length change measurement in optical fibers N2 - We present a novel technique to measure length changes between multiple reflection points in optical fibers. The technique allows for dynamic measurement up to 1kHz and a resolution better than 1µm. T2 - International conference "Optical sensors" CY - Karlsruhe, Germany DA - 2010-06-21 PY - 2010 DO - https://doi.org/10.1364/SENSORS.2010.STuB5 IS - STuB5 SP - 1 EP - 2 AN - OPUS4-21626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander T1 - Protection of critical infrastructure using fiber optic sensors embedded in technical textiles N2 - Terrorists and criminals more and more attack and destroy important infrastructures like routes, railways, bridges, tunnels, dikes and dams, important buildings. Therefore, reliable on-line and long-term monitoring systems are required to protect such critical infrastructures. Fiber optic sensors are well-suited for that. They can be installed over many kilometers and are able to measure continuously distributed strain, pressure, temperature and further mechanical and physical quantities. The very tiny optical fibers can be integrated into structures and materials and can provide information about any significant changes or damages of the structures. These so-called smart materials and smart structures are able to monitor itself or its environment. Particularly smart technical textiles with embedded fiber optic sensors have become very attractive because of their high importance for the structural health monitoring of geotechnical and masonry infrastructures. Such textiles are usually used for reinforcement of the structures; the embedded fiber optic sensors provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, critical infrastructures can be preventively protected. The paper will introduce this innovative field and will present the results achieved within several German and European projects. T2 - Fiber optic sensors and applications VII CY - Orlando, FL, USA DA - 2010-04-07 KW - Distributed sensors KW - Brillouin sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - POF OTDR KW - Strain sensors KW - Technical textiles KW - Geotextiles KW - Fiber optic sensors PY - 2010 SN - 9780819481412 DO - https://doi.org/10.1117/12.851013 SN - 0277-786X VL - 7677 IS - 767707 SP - 1 EP - 14 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-21675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - A novel quasi-distributed fibre optic displacement sensor for dynamic measurement N2 - We present a novel technique based on incoherent optical frequency domain reflectometry (OFDR) to measure length changes quasi-distributed between reflection points in optical fibres. The technique enables length changes to be measured with a resolution better than 1 µm and allows for static and dynamic measurement capabilities up to 2 kHz. We demonstrate that dynamic measurements of multiple fibre sections can be conducted independently from each other with high precision. Due to the precise and dynamic measurement capabilities, the proposed sensor system is expected to open new fields of application, especially in the structural-health-monitoring sector. Possible applications are discussed in the paper. KW - Strain sensor KW - Optical frequency domain reflectometry KW - OFDR KW - Optical fibre KW - Fibre sensors KW - Quasi-distributed sensors KW - Dynamic strain measurement PY - 2010 UR - http://iopscience.iop.org/0957-0233/21/7/075205/pdf/0957-0233_21_7_075205.pdf DO - https://doi.org/10.1088/0957-0233/21/7/075205 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 7 SP - 075205-1 - 075205-6 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-21812 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Peter A1 - Liehr, Sascha A1 - Nöther, Nils A1 - Wendt, Mario A1 - Wosniok, Aleksander A1 - Schneider-Gloetzl, J. A1 - Gloetzl, R. T1 - Distributed fibre optic sensors embedded in technical textiles for monitoring of geotechnical and masonry structures T2 - Monitoring technologies workshop - MoDeRn (Proceedings) CY - Troyes, France DA - 2010-06-07 PY - 2010 IS - OP.7 SP - 71 EP - 72 AN - OPUS4-23041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Witt, Jens A1 - Schukar, Marcus ED - Ecke, Wolfgang ED - Kara J. Peters, ED - Norbert G. Meyendorf, T1 - Smart technical textiles with integrated POF sensors N2 - Fiber optic sensors based on polymer optical fibers (POF) take advantage of the high elasticity and high break-down strain of POF. Because of their outstanding elastic properties, POF are well suited for integration into technical textiles like geotextiles and medical textiles. Smart textiles with incorporated POF sensors, able to sense various mechanical and physical quantities, can be realized. The integration of POF as a sensor into geotextiles for monitoring of displacement of soil is very attractive since POF can be used for distributed strain measurement of strain values of more than 40 %. An online monitoring of critical mechanical deformations of geotechnical structures like dikes, dams, slopes, embankments as well as of masonry structures can be ensured. Medical textiles that incorporate POF sensors can control vital physiological parameters like respiratory movement and can be used for wearable health monitoring of patients requiring a continuous medical assistance and treatment. The biocompatibility of POF is an important criterion for selecting POF as a medical sensor. The paper shows selected examples of using POF sensors for the mentioned monitoring purposes. T2 - Smart Sensor Phenomena, Technology, Networks, and Systems 2008 CY - San Diego, California, USA DA - 2008-03-10 KW - Fiber optic sensors KW - Polymer optical fibers (POF) KW - POF sensors KW - Geotextiles KW - Medical textiles KW - Strain sensor KW - Respiratory monitoring KW - POF OTDR KW - Distributed sensor KW - Geotechnical structures PY - 2008 SN - 978-0-8194-7119-2 DO - https://doi.org/10.1117/12.776758 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 6933 IS - 6933 SP - 69330V-1 - 69330V-15 PB - SPIE CY - Bellingham AN - OPUS4-17680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Krebber, Katerina A1 - Seeger, M. A1 - Thiele, E. A1 - Metschies, H. A1 - Gebreselassie, B. A1 - Münich, J.C. A1 - Stempniewski, L. ED - Francis Berghmans, ED - Mignani, Anna Grazia ED - Cutolo, Antonello ED - Patrick P. Meyrueis, ED - Thomas P. Pearsall, T1 - Distributed strain measurement with polymer optical fibers integrated into multifunctional geotextiles N2 - Fiber optic sensors based on polymer optical fibers (POF) have the advantage of being very elastic and robust at the same time. Unlike silica fibers, standard PMMA POF fibers can be strained to more than 40% while fully maintaining their light guiding properties. We investigated POF as a distributed strain sensor by analysing the backscatter increase at the strained section using the optical time domain reflectometry (OTDR) technique. This sensing ability together with its high robustness and break-down strain makes POF well-suited for integration into technical textiles for structural health monitoring purposes. Within the European research project POLYTECT (Polyfunctional textiles against natural hazards) technical textiles with integrated POF sensors, among others sensors are being developed for online structural health monitoring of geotechnical structures. Mechanical deformation in slopes, dams, dikes, embankments and retrofitted masonry structures is to be detected before critical damage occurs. In this paper we present the POF strain sensor properties, reactions to disturbing influences as temperature and bends as well as the results of the different model tests we conducted within POLYTECT. We further show the potential of perfluorinated graded-index POF for distributed strain sensing with increased spatial resolution and measurement lengths. T2 - Optical Sensors 2008 CY - Strasbourg, France DA - 2008-04-07 KW - Fiber optic sensors KW - OTDR KW - Polymer optical fibers (POF) KW - POF sensors KW - Distributed sensor KW - Strain sensor KW - Geotextiles KW - Structural health monitoring PY - 2008 SN - 978-0-8194-7201-4 DO - https://doi.org/10.1117/12.780508 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 7003 IS - 7003 SP - 700302-1 - 700302-15 PB - SPIE CY - Bellingham AN - OPUS4-17951 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Perfluorinated graded-index polymer optical fibers for distributed measurement of strain T2 - 17th International Conference on Plastic Optical Fibers CY - Santa Clara, CA, USA DA - 2008-08-26 PY - 2008 AN - OPUS4-18157 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Distributed polymer optical fiber sensors integrated in technical textiles for monitoring of masonry structures T2 - 4th International Conference on Structural Health Monitoring of Intelligent Infrastructure CY - Zurich, Switzerland DA - 2009-07-22 PY - 2009 AN - OPUS4-18988 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina ED - Jones, J. ED - Culshaw, B. ED - Ecke, W. ED - López-Higuera, J.M. ED - Willsch, R. T1 - Distributed perfluorinated POF strain sensor using OTDR and OFDR techniques T2 - 20th International conference on optical fibre sensors (Proceedings of SPIE) CY - Edinburgh, Scotland, UK DA - 2009-10-05 KW - Distributed strain sensor KW - Optical fiber sensor KW - Polymer optical fiber KW - POF sensor KW - Structural health monitoring KW - OTDR KW - OFDR PY - 2009 SN - 978-0-8194-7814-6 SN - 0277-786X SP - 75036G-1 - 75036G-4 PB - SPIE, the International Society for Optical Engineering AN - OPUS4-20289 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Seeger, M. A1 - Thiele, E. A1 - Metschies, H. A1 - Gebreselassie, B. A1 - Münich, J.C. T1 - Polymer optical fiber sensors for distributed strain measurement and application in structural health monitoring N2 - Polymer optical fiber (POF) sensors have the unique ability to measure high strain distributed along the fiber up to 40% using the optical time-domain reflectometry (OTDR) technique. Both, standard PMMA fibers and perfluorinated (PF) graded-index (GI) POF are introduced and evaluated in potential use and applicability. Further, distributed length change measurement based on cross-correlation analysis of the characteristic fiber signature of PF POF is introduced. We conclude the advances in distributed POF strain sensors technology with respect to application in structural health monitoring. Special focus is on the sensor integration into technical textiles for health monitoring of geotechnical structures and masonry structures. Measurement results of sensor-equipped textiles in different model tests are presented, displacement of soil and cracks in retrofitted masonry structures are detected and evaluated. KW - Distributed strain sensor KW - Optical fiber sensor KW - POF sensors KW - Structural health monitoring PY - 2009 DO - https://doi.org/10.1109/JSEN.2009.2018352 SN - 1530-437X SN - 1558-1748 VL - 9 IS - 11 SP - 1330 EP - 1338 CY - New York, NY, USA AN - OPUS4-20311 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Gabino, L. A1 - Krywult, J. ED - Klapperich, Herbert ED - Jacob, Dieter ED - Azzam, Rafig ED - Wolf, Rainer T1 - Eine neue Geotextilmessmatte mit verteilter Sensortechnik im Einsatz - Suche einer geeigneten Baustelle, Einbauerfahrungen und erste Ergebnisse T2 - 4. Symposium Umweltgeotechnik & 5. Freiberger Geotechnik-Kolloquium & Fachausstellung CY - Freiberg, Deutschland DA - 2009-06-04 PY - 2009 SN - 1613-4753 IS - Publication 7 SP - 1 EP - 9(?) CY - Freiberg AN - OPUS4-20400 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Glötzl, R. A1 - Schneider-Glötzl, J. A1 - Liehr, Sascha A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Gabino, L. A1 - Krywult, J. A1 - Krywult, L. T1 - First results of a field test in Belchatow brown coal mine to investigate creeping slopes T2 - VI. International brown coal mining congress "Brown coal - energy - environment - future" CY - Belchatów, Poland DA - 2009-05-18 PY - 2009 SN - 978-83-88316-85-2 SP - 57 EP - 64 PB - Art-Teskt CY - Kraków, Poland AN - OPUS4-20401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Distributed strain measurement in perfluorinated polymer optical fibres using optical frequency domain reflectometry N2 - We present the latest advances in distributed strain measurement in perfluorinated polymer optical fibres (POFs) using backscatter techniques. Compared to previously introduced poly(methyl methacrylate) POFs, the measurement length can be extended to more than 500 m at improved spatial resolution of a few centimetres. It is shown that strain in a perfluorinated POF can be measured up to 100%. In parallel to these investigations, the incoherent optical frequency domain reflectometry (OFDR) technique is introduced to detect strained fibre sections and to measure distributed length change along the fibre with sub-millimetre resolution by applying a cross-correlation algorithm to the backscatter signal. The overall superior performance of the OFDR technique compared to the optical time domain reflectometry in terms of accuracy, dynamic range, spatial resolution and measurement speed is presented. The proposed sensor system is a promising technique for use in structural health monitoring applications where the precise detection of high strain is required. KW - Distributed strain sensor KW - Optical fibre sensor KW - Polymer optical fibre KW - POF sensor KW - Structural health monitoring KW - OTDR KW - OFDR PY - 2010 DO - https://doi.org/10.1088/0957-0233/21/9/094023 SN - 0957-0233 SN - 1361-6501 VL - 21 IS - 9 SP - 094023-1 - 094023-6 PB - IOP Publ. Ltd. CY - Bristol AN - OPUS4-22379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - A novel fiber optic technique for quasi-distributed and dynamic measurement of length change and refractive index N2 - We present a novel technique for dynamic and simultaneous measurement of displacement and refractive indices at multiple reflection points in optical fibers. This quasi-distributed sensor is based on the incoherent optical frequency domain reflectometry (I-OFDR) technique and allows for m-resolution length change measurement and precise refractive index measurement. We show that the dynamic measurement ability and the simple sensor design allows for new applications in the field of structural health monitoring and chemical process control. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - Quasi-distributed sensor KW - Strain sensor KW - Length change measurement KW - Optical fiber sensor KW - Refractive index sensor KW - Structural health monitoring KW - OFDR PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.866325 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76532V-1 - 76532V-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-22380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - Quasi-distributed and dynamic length change measurement in polymer optical fibers N2 - We present a novel technique based on the incoherent optical frequency domain reflectometry (l-OFDR) technique for dynamic (2 kHz) and quasi-distributed length change measurement in polymer optical fibers (POF). The extreme strain sensing capabilities (> 125 %) and cyclic load behaviour of perfluorinated POF are investigated using this technique. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Wendt, Mario A1 - Krebber, Katerina T1 - Distributed strain and length change measurement in POF using optical frequency domain reflectometry N2 - We show that the incoherent optical frequency domain (l-OFDR) technique provides superior performance compared to standard OTDR techniques in terms of spatial resolution and measurement time. The distributed strain measurement capabilities of perfluorinated POF up 100 % strain are shown and distributed length change measurement using correlation techniques and OFDR are presented. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina A1 - Lenke, Philipp A1 - Liehr, Sascha A1 - Schukar, Marcus A1 - Wendt, Mario A1 - Witt, Jens T1 - Distributed POF sensors - recent progress and new challenges N2 - The potential of the use of POF as distributed sensors in several application fields has been successfully demonstrated. The distributed POF sensors have moved from the laboratory to the field. The paper presents the recent progress in the development of distributed POF sensors and addresses the main challenges to this innovative technology. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 IS - Sensors-2 SP - 1 EP - 4 AN - OPUS4-22305 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Distributed strain and length change measurement in POF using optical frequency domain reflectometry T2 - 19th International Conference on Plastic Optical Fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 AN - OPUS4-22418 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha T1 - Quasi-distributed and dynamic length change measurement in polymer opical fibers T2 - 19th International Conference on Plastic Optical Fibers CY - Yokohama, Japan DA - 2010-10-19 PY - 2010 AN - OPUS4-22419 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Stempniewski, L. A1 - Münich, C. A1 - Urban, M. A1 - Messervey, T. A1 - Zangani, D. A1 - Liehr, Sascha A1 - Sasek, L. ED - Mufti, A. ED - Banthia, N. T1 - Shaking table test of a two-storey stone masonry building reinforced with multifunctional textiles T2 - CSHM-3 - Conservation of heritage structures: using FRM and SHM CY - Ottawa, Canada DA - 2010-08-11 KW - Multiaxial textile KW - Fiber reinforced cement KW - Fiber matrix system KW - Shaking table tests KW - Polymer optical fibre KW - Fiber Bragg gratings PY - 2010 SN - 978-0-88865-883-8 SP - 71 EP - 81 CY - Vancouver, Canada AN - OPUS4-22605 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Liehr, Sascha A1 - Krebber, Katerina T1 - The impact of temperature and humidity on the backscatter profile of PMMA POF N2 - In this paper the influence of combined temperature and strain changes as well as changes of moisture content on polymer optical fibers made of polymethyl methacrylat (PMMA) is investigated. The increase of the scattering coefficient with increasing temperature for various strain levels is observed and quantified. The measurement results of influence of humidity on scattering intensity of PMMA-POF encourage to porpose these as a distributed humidity sensor. T2 - POF 2010 - 19th International conference on plastic optical fibers CY - Yokohama, Japan DA - 2010-10-19 KW - POF distributed sensing Rayleigh KW - Humiditiy KW - OTDR KW - Strain PY - 2010 SP - 1 EP - 7(?) AN - OPUS4-22685 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Liehr, Sascha A1 - Krebber, Katerina ED - Santos, J.L. ED - Culshaw, B. ED - López-Higuera, J.M. ED - MacPherson, W.N. T1 - Distributed humidity sensing based on Rayleigh scattering in polymer optical fibers N2 - In this document a new distributed sensor based on Rayleigh scattering in polymer optical fibers (POF) is proposed and first measurement results of the proposed sensor are shown. Different from Silica glas optical fibers POF absorb high quantities of water resulting in a change of their molecular structure and thereby reducing the present small scattering centers in areas of high humidity. The interdependence between scattering intensity and relative humidity is being investigated in case of steady cycles as well as stepwise changes of humidity and in the presence of moisture. A quantitative measure of humidity and scattering is presented. T2 - 4th European workshop on optical fibre sensors CY - Porto, Portugal DA - 2010-09-08 KW - POF KW - Distributed sensing KW - Rayleigh KW - Scattering KW - OTDR KW - Humidity PY - 2010 SN - 978-0-8194-8083-5 DO - https://doi.org/10.1117/12.866279 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE IS - 7653 SP - 76533X-1 - 76533X-4 PB - SPIE, the International Society for Optical Engineering CY - Bellingham, Wash. AN - OPUS4-22686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wosniok, Aleksander A1 - Krywult, L. A1 - Liehr, Sascha A1 - Krebber, Katerina A1 - Wendt, Mario A1 - Chrost, A. T1 - Monitoring konstrukcji ziemnych przy zastosowaniu rozlozonych przestrzennie swiatlowodowych sensorów optycznych, zintegrowanych w geosyntetykach KW - Fibre optic sensor KW - Spatial distributed sensor KW - Polymer optical fibre (POF) KW - Glass optical fibre (GOF) KW - POF OTDR KW - Brillouin sensor KW - BOTDA KW - BOFDA KW - Fibre Bragg grating (FBG) KW - Geosynthetics KW - Geotextiles KW - Technical textiles PY - 2011 UR - http://journals.bg.agh.edu.pl/GORNICTWO/2011-02/GG_2011_2_63.pdf SN - 1732-6702 SN - 0138-0990 VL - 35 IS - 2 SP - 597 EP - 604 PB - Uczelniane Wydawn. Naukowo-Dydaktyczne AGH CY - Kraków AN - OPUS4-23418 LA - pol AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -