TY - JOUR A1 - Habel, Wolfgang A1 - Krebber, Katerina T1 - Fiber-optic sensor applications in civil and geotechnical engineering N2 - Different types of fiber-optic sensors based on glass or polymeric fibers are used to evaluate material behavior or to monitor the integrity and long-term stability of load-bearing structure components. Fiber-optic sensors have been established as a new and innovative measurement technology in very different fields, such as material science, civil engineering, light-weight structures, geotechnical areas as well as chemical and high-voltage substations. Very often, mechanical quantities such as deformation, strain or vibration are requested. However, measurement of chemical quantities in materials and structure components, such as pH value in steel reinforced concrete members also provides information about the integrity of concrete structures. A special fiber-optic chemical sensor for monitoring the alkaline state (pH value) of the cementitious matrix in steel-reinforced concrete structures with the purpose of early detection of corrosion-initiating factors is described. The paper presents the use of several fiber-optic sensor technologies in engineering. One example concerns the use of highly resolving concrete-embeddable fiber Fabry-Perot acoustic emission (AE) sensors for the assessment of the bearing behaviour of large concrete piles in existing foundations or during and after its installation. Another example concerns fiber Bragg grating (FBG) sensors attached to anchor steels (micro piles) to measure the strain distribution in loaded soil anchors. Polymer optical fibers (POF) can be — because of their high elasticity and high ultimate strain – well integrated into textiles to monitor their Deformation behaviour. Such 'intelligent' textiles are capable of monitoring displacement of soil or slopes, critical mechanical deformation in geotechnical structures (dikes, dams, and embankments) as well as in masonry structures during and after earthquakes. KW - Fiber-optic sensor KW - Monitoring KW - Earthquake damage assessment KW - Steel-reinforced structures KW - pH sensor KW - Geotextiles KW - Distributed sensor PY - 2011 DO - https://doi.org/10.1007/s13320-011-0011-x SN - 1674-9251 VL - 1 IS - 3 SP - 268 EP - 280 PB - Springer CY - Heidelberg ; Secaucus, NJ AN - OPUS4-24256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nöther, N. A1 - Krebber, Katerina A1 - Schneider-Glötzl, J. T1 - An all-digital implementation of the Brillouin optical frequency domain analysis for long-range distributed strain and temperature monitoring N2 - For long-range measurements in geotechnical and industrial applications, distributed optical fiber sensors have become a tool of increasing importance throughout the past decade. Classic deformation monitoring (performed by strain gauges etc.) and temperature monitoring (Pt100 and alike) deliver data from fixed, single spots of a structure; quasidistributed measurements (fiber bragg gratings) provide a Chain of discrete measurement points along a limited sensing length. In contrast, an opticai fiber connected to a device for distributed strain and temperature sensing (DTSS) will provide a continuous profile of strain and temperature - spatially resolved down to less than 1 m - over a ränge of several tens of kilometers. In DTSS measurements, the nonlinear opticai effect of stimulated Brillouin Scattering (SBS) is employed: two light waves with a stable, tunable frequency offset are injected into opposite ends of the sensing fiber, where they will form a beat pattem, at which parts of the light will be scattered. By matching the frequency offset of the light waves to the propagation of acoustic fluctuation in the opticai fiber, a power transfer from one light wave to the other can be measured; since the acoustic propagation directly shifts with train and temperature of the fiber, these two quantities can be measured by tuning the light waves’ frequency offset. T2 - 8th International symposium on field measurements in geomechanics - FMGM 2011 CY - Berlin, Germany DA - 12.09.2011 PY - 2011 SP - 1 EP - 6 AN - OPUS4-24664 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Krebber, Katerina A1 - Demuth, J. A1 - Sasek, L. T1 - Fiber optic heart rate sensor for integration into personal protective equipment N2 - This paper reports on a fiber optic sensor for heart rate measurements. The sensor will be integrated into personal protective equipment within the framework of the FP7 EU project i-Protect. Two different sensor prototypes were developed. One is based on fiber Bragg gratings in silica fiber and the other one is based on macrobending effects in polymer optical fiber. T2 - International workshop BioPhotonics 2011 CY - Parma, Italy DA - 08.06.2011 KW - Smart textile KW - Healthcare monitoring KW - Fiber optical sensor KW - FBG KW - Heart rate sensor KW - Macrobending sensor PY - 2011 SN - 978-1-4244-9837-6 DO - https://doi.org/10.1109/IWBP.2011.5954836 IS - Th6.26 SP - 1 EP - 3 AN - OPUS4-24498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witt, Jens A1 - Breithaupt, Mathias A1 - Erdmann, Jessica A1 - Krebber, Katerina T1 - Humidity sensing based on microstructured POF long period gratings N2 - We investigated the capabilities of long period gratings (LPG) in single-mode microstructured polymer optical fibre (mPOF) for humidity sensing. For that mPOF LPGs were exposed to different humidity levels at a constant temperature of 30°C in a climate chamber. During the long term tests, which took up several weeks, the humidity was changed in several steps while mPOF LPG wavelength and fibre attenuation were measured. We also measured the water uptake of mPOF in environment with different relative humidity. T2 - POF 2011 - 20th International conference on plastic optical fibers CY - Bilbao, Spain DA - 14.09.2011 KW - Microstructured polymer optical fibre (mPOF) KW - Long period grating (LPG) KW - Humidity sensor PY - 2011 SP - 1 EP - 6 AN - OPUS4-24501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liehr, Sascha A1 - Krebber, Katerina ED - De Roeck, G. ED - Degrande, G. ED - Lombaert, G. ED - Müller, G. T1 - A novel quasi-distributed long-gauge fiber optic strain sensor system 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. T2 - EURODYN 2011 - 8th International conference on structural dynamics CY - Leuven, Belgium DA - 04.07.2011 KW - Distributed sensor KW - Strain sensor KW - Optical fiber sensor KW - Structural health monitoring KW - OFDR KW - Length change measurement KW - Dynamic sensor PY - 2011 SN - 978-90-760-1931-4 SP - 2097 EP - 2102 AN - OPUS4-24347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Krebber, Katerina T1 - Simultaneous measurement of temperature and strain distribution using Brillouin scattering in dispersion-shifted fibers N2 - We studied Brillouin gain spectrum characteristics in dispersion-shifted fibers having compound GeO2-doping compositions in the fiber core to realize simultaneous measurement of distributed strain and temperature. Due to various dopant concentration alongside the radius of tested nonzero dispersion-shifted fibers several multiple Brillouin scattering resonances were observed in the stimulated Brillouin spectra arose through backscattering on higher acoustic modes which propagated along the fiber axis. As a result of the varying acoustic velocities, the Brillouin resonance peaks featured different temperature coefficients which can be used to accomplish the simultaneous measurement of fiber strain and temperature. We presented our first measurement results for NZDS Fujikura and LEAF Corning fiber and discussed the superior sensory suitability of the former fiber types. T2 - IEEE Sensors 2011 conference CY - Limerick, Ireland DA - 28.10.2011 KW - Fiber optic sensor KW - Spatial distributed sensor KW - Brillouin gain spectrum (BGS) KW - Nonzero dispersion-shifted fiber (NZDSF) KW - Brillouin sensor KW - BOTDA KW - BOFDA PY - 2011 SN - 978-1-4244-9288-6 SP - 1476 EP - 1479 AN - OPUS4-24828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krebber, Katerina A1 - Habel, Wolfgang T1 - Fibre-optic sensors embedded in geotechnical textiles and concrete piles for structural health monitoring N2 - Fibre-optic sensors are more and more used in geotechnical and civil engineering. There are a big number of applications with the purpose of improvement or proof of the structural integrity. This paper, presents two examples where different fibre sensor types.are exploited for safety-relevant task in geotechnique. Technical textiles with embedded distributed fibre-optic sensors based on Brillouin Scattering in silica optical fibres and OTDR (optical time-domain reflectometry) in polymer optical fibres are presented. Such “smart” technical textiles can be used for reinforcement of geotechnical structures and masonry walls, and the embedded fibre-optic sensors can provide information about the condition of the structures as well as detect the presence of any damage and destructions in real time. Highly sensitive fibre-optic geophones based on Fabry-Perot sensors embedded in large concrete pile can be used for precise measurement of Deformation and wave distribution during static and dynamic pile test. Such sensors make the evaluation of the pile’s integrity and load-bearing capacity easier. KW - Faseroptischer Sensor KW - Verteilter Sensor KW - Brillouin-Sensor KW - Polymeroptischer Sensor KW - POF OTDR KW - Technisches Textil KW - Geotextil KW - Dehnungssensor KW - Geophon KW - Pfahltest KW - Akustische Welle KW - Fabry-Perot KW - Fibre-optic sensor KW - Distributed sensor KW - Polymer optical fibres (POF) KW - POF sensor KW - Strain sensor KW - Technical textiles KW - Geotextiles KW - Geophone KW - Fabry-Perot sensor KW - Pile test KW - Impact KW - Acoustic wave PY - 2011 SN - 0002-5968 VL - 7 SP - 252 EP - 263 PB - Wichmann CY - Heidelberg AN - OPUS4-24816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lenke, Philipp A1 - Wendt, Mario A1 - Krebber, Katerina A1 - Glötzl, R. ED - Bock, W.J. ED - Albert, J. ED - Bao, X. T1 - Highly sensitive fiber optic inclinometer - easy to transport and easy to install N2 - We present the status of our work on a tube shaped 3D deformation sensor based on continuously distributed fiber optic sensing. A sensor tube of very large diameter is used to ensure high sensitivity while the transportability and applicability are still comfortable due to our application strategy. The setup is designed to use different measurement techniques in the applied optical fibers including Brillouin based measurements and interferometric optical frequency domain measurements using an OBR 4400 from Luna Technologies. T2 - 21st International conference on optical fiber sensors (OFS 21) CY - Ottawa, Canada DA - 15.05.2011 KW - Inclinometer KW - Bend KW - Sensor KW - Fiber KW - Optic KW - Brillouin KW - OBR PY - 2011 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 7753 SP - 775352-1 EP - 775352-4 AN - OPUS4-24970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Structural health monitoring by smart technical textiles based on fiber optic sensors T2 - International Conference on Structural Health Monitoring of Intelligent Infrastructure, SHMII-5 CY - Cancún, Mexico DA - 2011-12-11 PY - 2011 AN - OPUS4-24960 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina ED - Ramos, G. A. T1 - Structural health monitoring by smart technical textiles based on fiber optic sensors N2 - Technical textiles with embedded distributed fiber optic sensors have been developed for the purposes of structural health monitoring in geotechnical and civil engineering. The distributed fiber optic sensors are based on Brillouin Scattering in silica optical fibers and OTDR in polymer optical fibers. Such “smart” technical textiles can be used for reinforcement of geotechnical and masonry structures and the embedded fiber optic sensors can provide information about the condition of the structures and detect the presence of any damages and destructions in real time. Thus, structural health monitoring of critical geotechnical and civil infrastructures can be realized. The paper highlights the results achieved in this innovative field in the framework of several German and European projects. T2 - SHMII-5 - 5th International conference on structural health monitoring of intelligent infrastructure CY - Cancún, Mexico DA - 11.12.2011 PY - 2011 IS - Keynote Lecture SP - 1 EP - 10 PB - National Autonomous University of Mexico CY - Mexico City AN - OPUS4-25261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Polymer Optical Fibres in Sensing - Applications & Future Demands T2 - IEEE Sensors 2011 Conference CY - Limerick, Ireland DA - 2011-10-28 PY - 2011 AN - OPUS4-24939 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Development of a PMMA-POF based fiber optic inclinometer with smart transport and installation characteristics T2 - 6th European Workshop on Structural Health Monitoring (EWSHM) CY - Dresden, Germany DA - 2012-06-03 PY - 2012 AN - OPUS4-26456 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Smart Technical Textiles Based on Fibre Optic Sensors - Technologies and Applications T2 - CIMTEC 2012: 4. International Conference "Smart Materials, Structures and Systems" CY - Montecatini Terme, Italy DA - 2012-06-10 PY - 2012 AN - OPUS4-26457 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - Fiber Optic Sensors in Technical Safety Sciences T2 - Workshop "Trends in Fiber Optics 2012" CY - Jena, Germany DA - 2012-02-23 PY - 2012 AN - OPUS4-26458 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - POF sensors for structural health monitoring - applications and future demands (invited presentation) T2 - 21st International Conference on Plastic Optical Fibers, POF 2012 CY - Atlanta, GA, USA DA - 2012-09-10 PY - 2012 AN - OPUS4-26792 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wosniok, Aleksander A1 - Mizuno, Y. A1 - Krebber, Katerina A1 - Nakamura, K. ED - Jaroszewicz, L.R. T1 - L-BOFDA: a new sensor technique for distributed Brillouin sensing N2 - We propose a new scheme of Brillouin optical frequency-domain analysis (BOFDA) for distributed fiber-optic strain and temperature sensing, named linear-configured BOFDA (L-BOFDA). In conventional loop-configured BOFDA, light injection into both ends of a fiber under test (FUT) is needed for counter-propagation of pump and probe waves. In contrast, in L-BOFDA, pump and probe waves are injected into the same end of an FUT, and the probe wave Fresnelreflected (or mirror-reflected) at the other end of the FUT is exploited; thus, one-end access is feasible. We show proof-of-concept results of distributed strain measurement in a silica single-mode fiber with L-BOFDA, and discuss the signal-to-noise ratio degradation and the benefit in developing distributed Brillouin sensors based on polymer optical fibers. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - Brillouin optical frequency-domain analysis (BOFDA) KW - L-BOFDA KW - Optical fiber sensing KW - Distributed strain measurement KW - Stimulated Brillouin scattering KW - Polymer optical fiber PY - 2013 DO - https://doi.org/10.1117/12.2025378 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8794 IS - Paper 8794 - 181 SP - 879431-1 EP - 879431-4 AN - OPUS4-28961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Habel, Wolfgang A1 - Krebber, Katerina T1 - Application of fiber-optic sensors for health monitoring purposes in geo-engineering T2 - 4th International forum on opto-electronic sensor-based monitoring in geo-engineering CY - Suzhou, China DA - 2012-10-11 KW - BOFDA KW - Fibre-optic sensor KW - Distributed sensor KW - Brillouin sensor KW - Polymer optical fibers (POF) KW - POF sensor KW - POF OTDR KW - Strain sensor KW - Technical textiles KW - Geotextiles KW - Geophone KW - Fabry-Perot sensor KW - Pile test KW - Impact KW - Acoustic wave PY - 2012 SP - 4 EP - 15 AN - OPUS4-27259 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liehr, Sascha A1 - Burgmeier, J. A1 - Krebber, Katerina A1 - Schade, Wolfgang T1 - Femtosecond laser structuring of polymer optical fibers for backscatter sensing N2 - Focused femtosecond laser pulses are used to create scattering damage in the core of polymer optical fibers (POF). The resulting structures are investigated regarding morphology by light microscopy and backscattered intensity using optical time domain reflectometry (OTDR). Quasi-distributed optical fiber sensing is proposed by evaluating backscatter changes at the inscribed scatter centers. Application examples for quasi-distributed measurement of fiber bends and temperature are demonstrated. KW - Femtosecond laser KW - Micromachining KW - Optical fiber sensors KW - Polymer optical fiber KW - Polymer PY - 2013 DO - https://doi.org/10.1109/JLT.2013.2250483 SN - 0733-8724 SN - 1558-2213 VL - 31 IS - 9 SP - 1418 EP - 1425 PB - Institute of Electrical and Electronics Engineers CY - New York, NY AN - OPUS4-28733 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - POFs for sensing applications N2 - The paper highlights the use of polymer optical fibers (POFs) as sensors in selected applications like structural health monitoring in geotechnical and civil engineering, composites monitoring, healthcare monitoring and personnel protection. The recent progress achieved in this field will be reviewed and the main challenges to these innovative fibre optic sensors will be adressed. T2 - 3rd Workshop on specialty optical fibers and their applications CY - Sigtuna, Sweden DA - 28.08.2013 PY - 2013 IS - T3.6 SP - 1 EP - 2 AN - OPUS4-29334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krebber, Katerina T1 - POFs for Sensing Applications T2 - Workshop on Specialty Optical fiber and their Applications (WSOF) CY - Sigtuna, Sweden DA - 28.08.2013 PY - 2013 AN - OPUS4-29256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Hicke, Konstantin A1 - Krebber, Katerina T1 - Temperature and humidity discrimination in Brillouin distributed fiber optic sensing using machine learning algorithms N2 - In the last few years, the use of machine learning has emerged in the field of distributed fiber optic sensors as a promising approach to enhance their performance and provide new capabilities. In this study, we use machine learning for simultaneous measurements of temperature and humidity in polyimide (PI)-coated optical fibers based on Brillouin Brillouin optical frequency domain analysis (BOFDA). Different non-linear machine learning algorithms are employed, namely polynomial regression, decision trees and artificial neural networks (ANNs), and their discrimination performance is benchmarked against that of the conventional linear regression. The performance is evaluated using leave-one-out cross-validation to ensure that the models are reliable and able to generalize well on new data. We show that nonlinear machine learning algorithms outperform the conventional linear regression and thus could pave the way towards simultaneous cost-effective temperature and humidity distributed sensing, which has the potential to find attractive new applications in the field of civil and geotechnical engineering, from structural health monitoring of dikes and bridges to subsea cables and long pipelines corrosion detection. T2 - SPIE Photonics Europe 2022 CY - Strasbourg, France DA - 03.04.2022 KW - Distributed Brillouin sensing KW - Machine learning KW - Artificial neural networks KW - Simultaneous temperature and humidity sensing KW - BOFDA PY - 2022 DO - https://doi.org/10.1117/12.2620985 VL - 12139 SP - 1 EP - 7 PB - SPIE AN - OPUS4-54861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Krebber, Katerina T1 - Verteilte faseroptische Sensoren zur Zustandsüberwachung von Verbundwerkstoff-Druckbehältern T1 - Distributed fiber optic sensors for structural health monitoring of composite pressure vessels N2 - In diesem Beitrag geben wir einen umfassenden Überblick über unsere Forschung auf dem Gebiet der verteilten faseroptischen Sensorik für die strukturelle Zustandsüberwachung von Wasserstoffdruckbehältern aus Verbundwerkstoffen. Insbesondere zeigen wir, wie die Integration von faseroptischen Sensoren in Druckbehälter aus Verbundwerkstoffen die Sicherheit erhöht und gleichzeitig die Wartungskosten senkt. Die geringe Größe von Lichtwellenleitern ermöglicht ihre Integration in Verbundwerkstoffstrukturen während des Herstellungsprozesses, wodurch eine kontinuierliche Überwachung sowie eine präzise Erkennung und Lokalisierung von Strukturschäden während des Betriebs der Druckbehälter ermöglicht wird. Wir erörtern auch das Potenzial modernster Signalverarbeitungsmethoden und des maschinellen Lernens für die Weiterentwicklung der vorausschauenden Instandhaltung. Die von uns vorgestellten Anwendungen von faseroptischen Sensoren zeigen, dass sie einen wichtigen Beitrag zur Energiewende hin zu erneuerbaren Energien leisten können. KW - Verteilte faseroptische Sensoren KW - Verbundwerkstoffe KW - Wasserstoff-Druckbehälter KW - Strukturüberwachung KW - Maschinelles Lernen PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596290 DO - https://doi.org/10.1515/teme-2023-0170 SN - 0171-8096 SP - 1 EP - 12 AN - OPUS4-59629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Karapanagiotis, Christos A1 - Schukar, Marcus A1 - Breithaupt, Mathias A1 - Krebber, Katerina T1 - Monitoring of composite pressure vessels using surface applied distributed fiber optic sensors N2 - In this paper, we report on surface-applied distributed fibre optic sensors for monitoring composite pressure vessels designed for hydrogen storage. Previous reports have revealed that integrating optical fibres within vessel composite structures effectively enables the monitoring of structural behavior throughout their lifetime. However, integrating optical fibres during the manufacturing process is complex and time-consuming. Therefore, we aim to simplify this process by attaching the optical fibres to the vessel’s surface. This method is significantly more timeefficient than the integration process and can be applied to any vessel. Our results demonstrate that surface-applied fibre optic sensors can detect and precisely localise damage. Additionally, signs of damage can be recognised even before the damage occurs. Predictive maintenance using fibre optic sensors could reduce premature maintenance costs and periodic inspections while increasing safety and extending the vessel’s useful service life. The role of machine learning in predictive maintenance is also discussed. T2 - 20th Sensors & their Applications Conference CY - Limerick, Ireland DA - 11.08.2024 KW - Hydrogen KW - Fiber optic sensors KW - Composites KW - Machine learning KW - Structural health monitoring PY - 2024 SP - 1 EP - 4 AN - OPUS4-60911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stajanca, Pavol A1 - Woyessa, G. A1 - Schukar, Marcus A1 - Bang, O. A1 - Krebber, Katerina T1 - Response of microstructured plastic optical fiber Bragg grating to gamma radiation N2 - Response of PMMA-based plastic optical fiber Bragg grating (FBG) to gamma radiation is investigated for the first time. FBG wavelength shift as large as 150 pm is observed for irradiation to 18 kGy. T2 - 5th Workshop on specialty optical fibers and their applications CY - Limassol, Cyprus DA - 11.10.2017 KW - Fiber Bragg gratings KW - Optical sensing and sensors KW - Plastic optical fibers KW - Gamma radiation PY - 2017 SP - Poster 19, 1 EP - 2 AN - OPUS4-42586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -