<?xml version="1.0" encoding="utf-8"?>
<export-example>
  <doc>
    <id>31039</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>91576S-1</pageFirst>
    <pageLast>91576S-4</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>9157</volume>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>International society for optics and photonics (SPIE)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Simultaneous vibration and quasi-distributed strain measurement using incoherent OFDR and extrinsic Fabry-Perot interferometers</title>
    <abstract language="eng">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.</abstract>
    <parentTitle language="eng">OFS2014 - 23rd International conference on optical fibre sensors (Proceedings)</parentTitle>
    <identifier type="old">34029</identifier>
    <identifier type="doi">10.1117/12.2059616</identifier>
    <identifier type="issn">0277-786X</identifier>
    <identifier type="issn">1996-756X</identifier>
    <note>Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE</note>
    <enrichment key="eventName">OFS2014 - 23rd International conference on optical fibre sensors</enrichment>
    <enrichment key="eventPlace">Santander, Spain</enrichment>
    <enrichment key="eventStart">02.06.2014</enrichment>
    <enrichment key="eventEnd">06.06.2014</enrichment>
    <enrichment key="date_peer_review">14.07.2014</enrichment>
    <author>Milan Steffen</author>
    <author>Sascha Liehr</author>
    <author>Frank Basedau</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical fibre sensor</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>EFPI</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>I-OFDR</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Quasi-distributed</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Strain</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Dynamic length and power management</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>35927</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>98861Q-1</pageFirst>
    <pageLast>98861Q-6</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>9886</volume>
    <type>conferenceobject</type>
    <publisherName>SPIE</publisherName>
    <publisherPlace>Bellingham, USA</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">On-line monitoring of gamma irradiated perfluorinated polymer optical fiber</title>
    <abstract language="eng">In this paper, we present the first results regarding the on-line monitoring of gamma-ray exposure effects on a commercial multi-mode perfluorinated polymer optical fiber (PF-POF), type GigaPOF-50SR from Chromis Fiberoptics. Our focus was to evaluate on-line the radiation induced attenuation (RIA) over a wide spectral range (320 nm – 1700 nm), in order to assess the fiber’s radiation hardness and its possible use in radiation detection. An Ocean Optics QE65000 high sensitivity spectrometer and a StellarNet near-IR spectrometer were used to cover the spectral ranges 200 nm – 1μm and 900 nm – 1.6 μm, respectively. Electron paramagnetic resonance was used to monitor the recovery of the irradiation induced centers at room temperature. The study indicated that the optical fiber can be used as radiation monitor at low dose rates by measuring the attenuation in the UV, while higher dose rates irradiation can be observed by RIA monitoring at specific wavelengths in the visible spectral range.</abstract>
    <parentTitle language="eng">Proc. of SPIE</parentTitle>
    <identifier type="doi">10.1117/12.2230688</identifier>
    <enrichment key="eventName">Photonics Europe 2016, Micro-Structured and Specialty Optical Fibers IV</enrichment>
    <enrichment key="eventPlace">Brussels, Belgium</enrichment>
    <enrichment key="eventStart">03.04.2016</enrichment>
    <enrichment key="eventEnd">07.04.2016</enrichment>
    <enrichment key="date_peer_review">05.01.2017</enrichment>
    <author>D. Sporea</author>
    <author>L. Mihai</author>
    <author>Daniel Negut</author>
    <author>Pavol Stajanca</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>electron paramagnetic resonance spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Perfluorinated polymer optical fiber</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>radiation effects</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>gamma irradiation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>radiation hardness</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>radiation induced attenuation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>radiation dosimetry</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Graue Literatur</collection>
  </doc>
  <doc>
    <id>35928</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>988619-1</pageFirst>
    <pageLast>988619-6</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>9886</volume>
    <type>conferenceobject</type>
    <publisherName>SPIE</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Creation of a microstructured polymer optical fiber with UV Bragg grating inscription for the detection of extensions at temperatures up to 125°C</title>
    <abstract language="eng">We describe the fabrication of a polycarbonate (PC) micro-structured polymer optical fiber (mPOF) and the writing of fiber Bragg gratings (FBGs) in it to enable strain and temperature measurements. We demonstrate the photosensitivity of a dopant-free PC fiber by grating inscription using a UV laser. We further show that PC Bragg gratings can be extended up to at least 3% without affecting the initial functionality of the micro-structured fiber. The response of PC FBGs to temperature up to 125°C is also investigated. Polycarbonate has good mechanical properties and its high temperatureresistance might extend the range of application of polymeric FBGs.</abstract>
    <parentTitle language="eng">Proc. of SPIE</parentTitle>
    <identifier type="doi">10.1117/12.2227843</identifier>
    <enrichment key="eventName">Photonics Europe 2016, Micro-Structured and Specialty Optical Fibres IV</enrichment>
    <enrichment key="eventPlace">Brussels, Belgium</enrichment>
    <enrichment key="eventStart">03.04.2016</enrichment>
    <enrichment key="eventEnd">07.04.2016</enrichment>
    <enrichment key="date_peer_review">05.01.2017</enrichment>
    <author>A. Fasano</author>
    <author>G. Woyessa</author>
    <author>Pavol Stajanca</author>
    <author>C. Markos</author>
    <author>A. Stefani</author>
    <author>K. Nielsen</author>
    <author>H. K. Rasmussen</author>
    <author>Katerina Krebber</author>
    <author>O. Bang</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>fiber Bragg gratings</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Polycarbonate</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>polymers</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>micro-structured polymer optical fibers</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>UV laser inscription</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>optical fiber sensors</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Graue Literatur</collection>
  </doc>
  <doc>
    <id>35948</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>4437</pageFirst>
    <pageLast>4444</pageLast>
    <pageNumber/>
    <edition/>
    <issue>19</issue>
    <volume>34</volume>
    <type>article</type>
    <publisherName>IEEE</publisherName>
    <publisherPlace>Piscataway, NJ, USA</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Random quadrature demodulation for direct detection single-pulse rayleigh C-OTDR</title>
    <abstract language="eng">We present a demodulation method that partially compensates for the nonlinear and random transfer function of fiber-optic direct detection coherent Rayleigh optical time-domain reflectometry (C-OTDR). Specifically, the proposed method is shown to improve the detection of small amplitude, high frequency dynamic optical fiber strain as it occurs in acoustic emission sensing. The method is applicable provided that the dynamic fiber strain to be sensed is known to affect a longer section of sensing fiber in a spatially homogeneous way. It is shown that this knowledge can be used to extract more quantitative information from the measured C-OTDR signal by averaging signal components from the affected fiber section in a suitable and efficient way. The theoretical basis of the method is developed and supporting experimental results are presented.</abstract>
    <parentTitle language="eng">Journal of Lightwave Technology</parentTitle>
    <identifier type="doi">10.1109/JLT.2016.2557586</identifier>
    <identifier type="issn">0733-8724</identifier>
    <enrichment key="date_peer_review">17.11.2016</enrichment>
    <author>Philipp Rohwetter</author>
    <author>René Eisermann</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical fiber sensors</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Coherent optical time-domain reflectometry (C-OTDR)</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fiber-optic speckle interferometry</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Remote acoustic emission sensing</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>36461</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>99160H-1</pageFirst>
    <pageLast>99160H-4</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>9916</volume>
    <type>conferenceobject</type>
    <publisherName>SPIE</publisherName>
    <publisherPlace>Bellingham, WA, USA</publisherPlace>
    <creatingCorporation>SPIE</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Perfluorinated polymer optical fiber for gamma radiation monitoring</title>
    <abstract language="eng">The sensitivity of low-loss perfluorinated polymer optical fiber (PF-POF) to gamma radiation is investigated for on-line radiation monitoring purposes. The radiation-induced attenuation (RIA) of a commercial PF-POF based on Cytop material is measured in the visible spectral region. The fiber RIA shows strong wavelength dependence with rapid increase towards the blue side of the spectrum. The wide range of radiation sensitivities is available via careful selection of appropriate monitoring wavelength. The accessible sensitivities span from 1.6 ± 0.2 dBm-1/kGy measured at 750 nm to 18.3 ± 0.7 dBm-1/kGy measured at 420 nm. The fairly high radiation sensitivity as well as its wide tunability makes the fiber a promising candidate for a broad range of applications.</abstract>
    <parentTitle language="eng">Proc. of SPIE</parentTitle>
    <identifier type="doi">10.1117/12.2235528</identifier>
    <identifier type="url">http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2525047&amp;resultClick=1</identifier>
    <enrichment key="eventName">Sixth European Workshop on Optical Fibre Sensors</enrichment>
    <enrichment key="eventPlace">Limerick, Ireland</enrichment>
    <enrichment key="eventStart">31.05.2016</enrichment>
    <enrichment key="eventEnd">03.06.2016</enrichment>
    <enrichment key="date_peer_review">25.07.2016</enrichment>
    <author>Pavol Stajanca</author>
    <author>L. Mihai</author>
    <author>D. Sporea</author>
    <author>D. Negut</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Perfluorinated polymer optical fiber</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cytop</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>gamma radiation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>optical fiber sensors</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>radiation dosimetry</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>51680</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>37058</pageFirst>
    <pageLast>37068</pageLast>
    <pageNumber/>
    <edition/>
    <issue>24</issue>
    <volume>28</volume>
    <type>article</type>
    <publisherName>Optical Society of America</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Direct detection based φOTDR using the Kramers-Kronig receiver</title>
    <abstract language="eng">A Kramers-Kronig (KK) receiver is applied to a phase-sensitive optical time domain reflectometry based on direct detection. An imbalanced Mach-Zehnder interferometer with a 2× 2 coupler is used in sensing system to encode the phase information into optical intensity. The directly obtained signal is treated as the in-phase component, and the KK receiver provides the quadrature component by Hilbert transform of the obtained signal, so that the optical phase can be retrieved by IQ demodulation. The working principle is well explained, and the obtained phase variance is theoretically analyzed. The experiment demonstrates the functionality of the sensor and validates the theoretical analysis.</abstract>
    <parentTitle language="eng">Optics Express</parentTitle>
    <identifier type="doi">10.1364/OE.405723</identifier>
    <identifier type="url">https://www.osapublishing.org/oe/fulltext.cfm?uri=oe-28-24-37058&amp;id=442839</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-516803</identifier>
    <enrichment key="date_peer_review">17.12.2020</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Xin Lu</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Kramers-Kronig detector</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed fiber sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acoustic sensing</value>
    </subject>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Security</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/51680/oe-28-24-37058.pdf</file>
  </doc>
  <doc>
    <id>52757</id>
    <completedYear/>
    <publishedYear>2021</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>18791</pageFirst>
    <pageLast>18806</pageLast>
    <pageNumber/>
    <edition/>
    <issue>12</issue>
    <volume>29</volume>
    <type>article</type>
    <publisherName>Optical Society of America</publisherName>
    <publisherPlace>Washington, DC</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Characterizing detection noise in phase-sensitive optical time domain reflectometry</title>
    <abstract language="eng">Phase-sensitive optical time domain reflectometry (φOTDR) is an excellent distributed fiber sensing technique and has been applied in various areas. Its noise is however never been comprehensively studied to the best of our knowledge. The different detection noise sources in such a sensing system are thoroughly investigated. The impacts of thermal noise, shot noise and the beat between signal and the amplified spontaneous emission from a pre-amplifier have been theoretically and experimentally demonstrated. Due to the random nature of the φOTDR signal, the detection noise demonstrates distinct features at different fiber positions in a single measurement. The theoretical analysis and the experimental result explicitly affirm most of the fiber sections, and the difference at some positions may be explained by ambient noise.</abstract>
    <parentTitle language="eng">Optics Express</parentTitle>
    <identifier type="doi">https://doi.org/10.1364/OE.424410</identifier>
    <identifier type="issn">1094-4087</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">05.07.2021</enrichment>
    <author>Xin Lu</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Noise analysis</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acoustic sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed fiber sensing</value>
    </subject>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Security</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>54391</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>6934</pageFirst>
    <pageLast>6948</pageLast>
    <pageNumber/>
    <edition/>
    <issue>5</issue>
    <volume>30</volume>
    <type>article</type>
    <publisherName>Optica Publishing Group</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Phase error analysis and unwrapping error suppression in phase-sensitive optical time domain reflectometry</title>
    <abstract language="eng">Phase-sensitive optical time domain reflectometry becomes an effective tool to realize distributed sensing, and the optical phase of the received light is usually used to quantify the strain for both dynamic and static measurement. The analysis on the overall phase error has been improved by considering the proportionality of the detection noise to the local optical power. The estimation accuracy is greatly improved by using the proposed theory, the probability density of the estimation accuracy over 99% is &gt; 0.6, ∼39 times larger than the previously reported method. The phase unwrapping may malfunction due to the noisy signal, causing large phase errors. Point break detection algorithms are used to locate the incorrect phase unwrapping points, so the temporal evolution of the phase retrieved at each position can be divided into several sections with different offset. The phase unwrapping error is then suppressed by removing the offset.</abstract>
    <parentTitle language="eng">Optics Express</parentTitle>
    <identifier type="doi">10.1364/OE.446517</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-543919</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">28.03.2022</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Xin Lu</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Phase unwrapping</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed fiber sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acoustic sensing</value>
    </subject>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/54391/oe-30-5-6934.pdf</file>
  </doc>
  <doc>
    <id>57030</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>11</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>13</volume>
    <type>article</type>
    <publisherName>Nature Portfolio</publisherName>
    <publisherPlace>London</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Phase-sensitive optical time domain reflectometry based on geometric phase measurement</title>
    <abstract language="eng">A phase-sensitive optical time domain reflectometer based on coherent heterodyne detection of geometric phase in the beat signal of light, is reported for the first time to our knowledge. The use of the geometric phase to extract strain makes it immune to polarisation diversity fading. This is because a polarisation mismatch between the interfering beams is not a hindrance to its measurement. The geometric phase is calculated using the amplitude of the beat signal and individual beam intensities without any need for phase unwrapping. It is measured per beat period and can be equated with the traditionally measured dynamic phase with appropriate scaling. The results show that the system based on the geometric phase successfully measures strain, free from polarisation mismatch fading and phase unwrapping errors, providing a completely novel solution to these problems.</abstract>
    <parentTitle language="eng">Scientific Reports</parentTitle>
    <identifier type="doi">10.1038/s41598-023-29972-4</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-570307</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">27.02.2023</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Sabahat Shaheen</author>
    <author>Konstantin Hicke</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fiber optic sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed acoustic sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DAS</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Geometric phase</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Pancharatnam–Berry phase</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Berry phase</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Umwelt</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Sensorik</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/57030/srep_geometric-phase-sensing__published.pdf</file>
  </doc>
  <doc>
    <id>59191</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>12</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1</issue>
    <volume>24</volume>
    <type>article</type>
    <publisherName>MDPI</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Blast-Assisted Subsurface Characterisation Using a Novel Distributed Acoustic Sensing Setup Based on Geometric Phases</title>
    <abstract language="eng">A novel DAS setup based on geometric phases in coherent heterodyne detection is applied for the first time to the characterisation of the Earth’s subsurface. In addition, an optimisation of the proposed setup in terms of its spatial resolution is also presented for the first time. The surface waves are generated by strong blasts of 25 kg of explosives at a dedicated test site. A 10 km dark fiber link in the vicinity of the test site connected to the test setup records the resulting strain signals. The spike-free and low-noise strain data thus obtained minimize post-processing requirements, making the setup a candidate for real-time seismic monitoring. An analysis of the dispersion characteristics of the generated surface waves is performed using a recently reported optimised seismic interferometric technique. Based on the dispersion characteristics, the shear wave velocities of the surface waves as a function of the depth profile of the Earth’s crust are determined using an optimised evolutionary algorithm.</abstract>
    <parentTitle language="eng">Sensors</parentTitle>
    <identifier type="doi">10.3390/s24010030</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-591913</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">30.01.2024</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Sabahat Shaheen</author>
    <author>Konstantin Hicke</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Geophysics</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Geometric Phase</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed Fiber Optic Sensor</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed Acoustic Sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Earthquake Monitoring</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Seismology</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Umwelt</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Sensorik</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/59191/Shaheen et al. - 2024 - Blast-Assisted Subsurface Characterisation Using a.pdf</file>
  </doc>
  <doc>
    <id>59612</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>8</pageLast>
    <pageNumber/>
    <edition/>
    <issue>18</issue>
    <volume>42</volume>
    <type>article</type>
    <publisherName>Optical Society und IEEE Photonics Society</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Distributed acoustic sensing to monitor ground motion/movement at multi-frequency bands</title>
    <abstract language="eng">A novel distributed acoustic sensing technique is proposed that exploits both phase and amplitude of the Rayleigh backscattered light to quantify the environmental variation. The system employs a wavelength-scanning laser and an imbalanced Mach-Zehnder interferometer to acquire the reflection spectra and the phase of the detected light, respectively. Fading-free and low-frequency measurements are realized via the crosscorrelation of the reflection spectra. The discrete crosscorrelation is used to circumvent the nonlinear frequency sweeping of the laser. Based on the phase of the backscattered light, it is possible to quantify fast environmental variations. The whole system requires no hardware modification of the existing system and its functionality is experimentally validated. The proposed system has the potential to monitor ground motion/movement at very low frequency band like subsidence around mining areas and at high frequency band like earthquakes and vibrations induced by avalanches.</abstract>
    <parentTitle language="eng">Journal of Lightwave Technology</parentTitle>
    <identifier type="doi">10.1109/JLT.2024.3358495</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-596129</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">06.11.2024</enrichment>
    <licence>Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International</licence>
    <author>Xin Lu</author>
    <author>Konstantin Hicke</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed acoustic sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>DAS</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed fiber optic sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ground motion detection</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Subsidence monitoring</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Umwelt</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Verkehrsinfrastrukturen</collection>
    <collection role="themenfelder" number="">Sensorik</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/59612/Distributed_acoustic_sensing_to_monitor_ground_motion_movement_at_multi-frequency_bands.pdf</file>
  </doc>
  <doc>
    <id>56049</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1837</pageFirst>
    <pageLast>1847</pageLast>
    <pageNumber/>
    <edition/>
    <issue>8</issue>
    <volume>1</volume>
    <type>article</type>
    <publisherName>Optica Publishing Group</publisherName>
    <publisherPlace>Washington, DC</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Approach for Faster Signal Processing in Փ-OTDR Systems Based on Directional Measurement of Fiber Slices Interaction</title>
    <abstract language="eng">In this study, a signal processing approach for heterodyne Փ-OTDR and C-OTDR systems that can obtain external perturbation and its frequency content in a faster way is proposed. We can detect vibrations with the same or better SNR using this processing approach, only with a single step and fast calculation. Fig. 12 shows the comparison of the normalized measurement time for the gamma matrix method and the conventional method throughout the three experiments. The speed of processing using a gamma matrix is ~35%–50% faster compared to a conventional method in high frequency test (PZT), low frequency test (walking) and street monitoring test. The processing speed in low frequency test is normally a bit lower than the similar high frequency one, since we must use higher number of time frames. Also, in street test we have higher speed because we can select wider gauges.</abstract>
    <parentTitle language="eng">Optics Continuum</parentTitle>
    <identifier type="doi">10.1364/OPTCON.456421</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-560492</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">20.10.2022</enrichment>
    <licence>Creative Commons - CC BY-NC - Namensnennung - Nicht kommerziell 4.0 International</licence>
    <author>Mohammadmasoud Zabihi</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Փ-OTDR</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Umwelt</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Sensorik</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/56049/Published.pdf</file>
  </doc>
  <doc>
    <id>56051</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>19990</pageFirst>
    <pageLast>19998</pageLast>
    <pageNumber/>
    <edition/>
    <issue>11</issue>
    <volume>30</volume>
    <type>article</type>
    <publisherName>Optica</publisherName>
    <publisherPlace>Washington, DC</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Laser source frequency drift compensation in Φ-OTDR systems using multiple probe frequencies</title>
    <abstract language="eng">In this study, an approach for mitigation of LSFD in Φ-OTDR systems was proposed. By using one probe pulse as a reference in a system with two or more probe frequencies, we can remove unwanted low frequency noise that is originally caused by the laser source. Although LSFD is problematic issue, it is not the only source of low frequency noise. Change in temperature, humidity, physical surroundings, environment, etc., can result in such noises. The proposed method; however, is expected to highly suppresses all of these effects, regardless of their source, either in the time or frequency domain.&#13;
For comparing reference and probe signals, there are sophisticated methods, rather than normal differentiation, available for use. Some of these methods have a close relationship with CPD methods and can further enhance the results. These methods can be further discussed in an independent research or future work.&#13;
The proposed method is very helpful for increasing accuracy in passive and active seismic monitoring, reservoir monitoring, underwater monitoring, etc. It also helps using relatively simpler laser sources and make the whole system price-efficient, as well as processing data without lengthy compensation algorithms.</abstract>
    <parentTitle language="eng">Optics Express</parentTitle>
    <identifier type="doi">10.1364/oe.460302</identifier>
    <identifier type="issn">1094-4087</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-560517</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">20.10.2022</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Mohammadmasoud Zabihi</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Frequency Drift</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Փ-OTDR</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>LSFD</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Umwelt</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Sensorik</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/56051/Published.pdf</file>
  </doc>
  <doc>
    <id>61420</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>9</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>181</volume>
    <type>article</type>
    <publisherName>Elsevier Ltd.</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Suppression of Rayleigh fading induced errors in φOTDR by different pulse widths for improving the reliability of civil infrastructure monitoring</title>
    <abstract language="eng">Rayleigh fading is a widely observed phenomenon in the many fields, such as wireless communication and optical imaging. It is also the main factor limiting the performance of the phase-sensitive optical time domain reflectometry (φOTDR). The low SNR at the fading points results in a large measurement error, severely affecting the reliability of civil infrastructure monitoring. The proposed method involves changing the pulse width during measurements to suppress the impact of fading. Experimental result shows that the number of fading points is greatly reduced by ∼ 96 % and the measurement error is reduced by more than 5 times. Unlike existing methods, this approach requires no hardware modifications, making it applicable to almost all current phase-based φOTDR systems. The versatility and effectiveness of this method make it an excellent candidate for infrastructure monitoring and related fields.</abstract>
    <parentTitle language="eng">Optics &amp; Laser Technology</parentTitle>
    <identifier type="doi">10.1016/j.optlastec.2024.111927</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-614208</identifier>
    <identifier type="issn">1879-2545</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="date_peer_review">04.11.2024</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Xin Lu</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed fiber sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical fiber sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Phase-sensitive optical time domain reflectometry</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Infrastructure monitoring</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Rayleigh fading</value>
    </subject>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <collection role="themenfelder" number="">Verkehrsinfrastrukturen</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/61420/1-s2.0-S0030399224013859-main.pdf</file>
  </doc>
  <doc>
    <id>60384</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>10</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>13001</volume>
    <type>conferenceobject</type>
    <publisherName>SPIE</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Distributed fiber optic sensing for monitoring of underground facilities</title>
    <abstract language="eng">Distributed fiber optic sensing (DFOS) technique is a promising and robust non-destructive testing tool that can seamlessly acquire environmental conditions over large scales. Therefore, it has found extensive applications in structural health monitoring. Its appeal for monitoring underground facilities lies in the intrinsic properties of the optical fiber, such as immunity to magnetic interference, small size, chemical inertia, etc. This paper provides a concise overview of DFOS applications in underground facility monitoring. Following a brief introduction to the workingbnprinciple of the DFOS technique, various examples are provided to demonstrate how distributed fiber sensors contribute to monitoring underground facilities. The paper presents unpublished field test results with an emphasis in the energy sector, including monitoring gas storage facilities, geothermal reservoir exploration, and ground movement detection. Furthermore, the paper identifies several directions for enhancing the DFOS system.</abstract>
    <parentTitle language="eng">Specialty Optical Fibres VIII</parentTitle>
    <identifier type="doi">10.1117/12.3023571</identifier>
    <identifier type="issn">0277-786X</identifier>
    <enrichment key="eventName">SPIE Photonics Europe</enrichment>
    <enrichment key="eventPlace">Strasbourg, France</enrichment>
    <enrichment key="eventStart">07.04.2024</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="eventEnd">12.04.2024</enrichment>
    <enrichment key="date_peer_review">09.09.2024</enrichment>
    <author>Xin Lu</author>
    <author>Konstantin Hicke</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Structure health monitoring</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Geothermal borehole</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed fiber optic sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ground movement</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Leakage detection</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="institutes" number="">8 Zerstörungsfreie Prüfung</collection>
    <collection role="institutes" number="">8.6 Faseroptische Sensorik</collection>
    <collection role="themenfelder" number="">Energie</collection>
    <collection role="themenfelder" number="">Infrastruktur</collection>
    <collection role="themenfelder" number="">Security</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
    <collection role="literaturgattung" number="">Graue Literatur</collection>
    <collection role="themenfelder" number="">Wasserstoff</collection>
    <collection role="themenfelder" number="">Verkehrsinfrastrukturen</collection>
  </doc>
  <doc>
    <id>37914</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>565</pageFirst>
    <pageLast>570</pageLast>
    <pageNumber/>
    <edition/>
    <issue>9</issue>
    <volume>54</volume>
    <type>article</type>
    <publisherName>NISCAIR</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Optical fiber defect detection using Brillouin optical time domain analyser</title>
    <abstract language="eng">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.</abstract>
    <parentTitle language="eng">Indian Journal of Pure &amp; Applied Physics</parentTitle>
    <identifier type="issn">0019-5596</identifier>
    <enrichment key="date_peer_review">25.10.2016</enrichment>
    <author>M. Kasinathan</author>
    <author>Aleksander Wosniok</author>
    <author>Katerina Krebber</author>
    <author>C. Babu Rao</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Stimulated Brillouin scattering</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed sensor</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Optical fiber</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Brillouin Optical Time Domain Analysis</value>
    </subject>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>44104</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>227</pageFirst>
    <pageLast>234</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>41</volume>
    <type>article</type>
    <publisherName>Elsevier Inc.</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Solution-mediated cladding doping of commercial polymer optical fibers</title>
    <abstract language="eng">Solution doping of commercial polymethyl methacrylate (PMMA) polymer optical fibers (POFs) is presented as a novel approach for preparation of custom cladding-doped POFs (CD-POFs). The presented method is based on a solution-mediated diffusion of dopant molecules into the fiber cladding upon soaking of POFs in a methanol-dopant solution. The method was tested on three different commercial POFs using Rhodamine B as a fluorescent dopant. The dynamics of the diffusion process was studied in order to optimize the doping procedure in terms of selection of the most suitable POF, doping time and conditions. Using the optimized procedure, longer segment of fluorescent CD-POF was prepared and its performance was characterized. Fiber’s potential for sensing and illumination applications was demonstrated and discussed. The proposed method represents a simple and cheap way for fabrication of custom, short to medium length CD-POFs with various dopants.</abstract>
    <parentTitle language="eng">Optical Fiber Technology</parentTitle>
    <identifier type="doi">10.1016/j.yofte.2018.02.008</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-441045</identifier>
    <identifier type="issn">1068-5200</identifier>
    <identifier type="issn">1095-9912</identifier>
    <enrichment key="date_peer_review">12.04.2018</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Pavol Stajanca</author>
    <author>Ievgeniia Topolniak</author>
    <author>Samuel Pötschke</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Polymer optical fiber</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solution doping</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Polymethyl methacrylate</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Rhodamine B</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Dye-doped fiber</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescent optical fiber</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/44104/2018_PStajanca_OFT_solution-mediated cladding doping of commercial polymer optical fibers.pdf</file>
  </doc>
  <doc>
    <id>45716</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>22307</pageFirst>
    <pageLast>22314</pageLast>
    <pageNumber/>
    <edition/>
    <issue>17</issue>
    <volume>26</volume>
    <type>article</type>
    <publisherName>Optical Society of America</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Humidity-induced Brillouin frequency shift in perfluorinated polymer optical fibers</title>
    <abstract language="eng">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.</abstract>
    <parentTitle language="eng">Optics Express</parentTitle>
    <identifier type="doi">10.1364/OE.26.022307</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-457165</identifier>
    <identifier type="issn">1094-4087</identifier>
    <enrichment key="date_peer_review">06.09.2018</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Andy Schreier</author>
    <author>Aleksander Wosniok</author>
    <author>Sascha Liehr</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Brillouin</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Polymer optical fibre</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Humidity</value>
    </subject>
    <collection role="ddc" number="620">Ingenieurwissenschaften und zugeordnete Tätigkeiten</collection>
    <collection role="ddc" number="624">Ingenieurbau</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/45716/oe-26-17-22307.pdf</file>
  </doc>
  <doc>
    <id>44907</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>106810O-1</pageFirst>
    <pageLast>106810O-7</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>10681</volume>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>SPIE</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Solution doping of commercial plastic optical fibers</title>
    <abstract language="eng">Solution doping of off-the-shelf plastic optical fibers (POFs) represents rather simple and cheap way for preparing custom cladding-doped POFs (CD-POFs) with short to medium lengths. CD-POFs are especially attractive for environmental sensing applications, but might be of interest for illumination task as well. In this work, the proposed doping technique is tested with three different commercial low-cost polymethyl methacrylate (PMMA) POFs; Eska CK-40 and Eska GK-40 from Mitsubishi Rayon and Raytela PGU-FB1000 from Toray. The aim of the work is to aid the selection of the most suitable fiber yielding highest optical quality of prepared CD-POFs. Firstly, the optimal doping times are determined for the individual fiber types using short fiber samples. Secondly, longer 10 m CD-POFs are prepared from all tested fibersusing the optimized doping procedure. Finally, attenuation of pristine POFs and prepared CD-POFs is measured using optical time domain reflectometry in order to characterize the impacts of the doping on fiber optical properties. In addition, the importance of post-doping drying procedure for CD-POF optical performance is investigated as well. The results suggest that, although doping of all tested fibers is generally feasible, Eska CK-40 is the most suitable candidate with regard to the Doping efficiency and fiber post-doping performance.</abstract>
    <parentTitle language="eng">Proc. SPIE / MICRO-STRUCTURED AND SPECIALTY OPTICAL FIBRES V</parentTitle>
    <identifier type="doi">10.1117/12.2315619</identifier>
    <identifier type="issn">0277-786X</identifier>
    <enrichment key="eventName">SPIE Photonics Europe 2018</enrichment>
    <enrichment key="eventPlace">Strasbourg, France</enrichment>
    <enrichment key="eventStart">22.04.2018</enrichment>
    <enrichment key="eventEnd">26.04.2018</enrichment>
    <enrichment key="date_peer_review">30.08.2018</enrichment>
    <author>Pavol Stajanca</author>
    <author>Ievgeniia Topolniak</author>
    <author>Samuel Pötschke</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Plastic optical fibers</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Solution doping</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Polzmethyl methacrylate</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>PMMA</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Rhodamine B</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fluorescent optical fibers</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cladding-doped fibers</value>
    </subject>
    <collection role="ddc" number="543">Analytische Chemie</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>44967</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1600, 1</pageFirst>
    <pageLast>9</pageLast>
    <pageNumber/>
    <edition/>
    <issue>5</issue>
    <volume>18</volume>
    <type>article</type>
    <publisherName>MDPI</publisherName>
    <publisherPlace>Basel, Switzerland</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">63 km BOFDA for temperature and strain monitoring</title>
    <abstract language="eng">We demonstrate (and are the first to do so) 63 km Brillouin Optical Frequency-Domain Analysis (BOFDA) for temperature and strain monitoring using a 100 km fiber loop. The use of BOFDA for long-range applications can be considered a novel approach, as previous investigations focused on the utilization of Brillouin Optical Time-Domain Reflectometry and Analysis (BOTDR and BOTDA, respectively). At 51.7 km, a 100 m hotspot (37 °C) was detected without using distributed Raman amplification or image processing.</abstract>
    <parentTitle language="eng">Sensors</parentTitle>
    <identifier type="doi">10.3390/s18051600</identifier>
    <identifier type="issn">1424-8220</identifier>
    <identifier type="urn">urn:nbn:de:kobv:b43-449679</identifier>
    <enrichment key="date_peer_review">25.05.2018</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Thomas Kapa</author>
    <author>Andy Schreier</author>
    <author>Katerina Krebber</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Distributed sensing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Stimulated Brillouin scattering</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Fiber optics sensors</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei für die Öffentlichkeit verfügbar ("Open Access")</collection>
    <collection role="unnumberedseries" number="">Wissenschaftliche Artikel der BAM</collection>
    <thesisPublisher>Bundesanstalt für Materialforschung und -prüfung (BAM)</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-bam/files/44967/2018 - Kapa - 63 km BOFDA for Temperature and Strain Monitoring.pdf</file>
  </doc>
</export-example>
