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Max Koeppel; Abhinav Sharma; Jasper Podschus; Sanju Sundaramahalingam; Nicolas Y. Joly; Shangran Xie; Philip St. J. Russell; Bernhard Schmauss. Doppler optical frequency domain reflectometry for remote fiber sensing: erratum. Optics Express 2021, 29, 24193 .
AMA StyleMax Koeppel, Abhinav Sharma, Jasper Podschus, Sanju Sundaramahalingam, Nicolas Y. Joly, Shangran Xie, Philip St. J. Russell, Bernhard Schmauss. Doppler optical frequency domain reflectometry for remote fiber sensing: erratum. Optics Express. 2021; 29 (15):24193.
Chicago/Turabian StyleMax Koeppel; Abhinav Sharma; Jasper Podschus; Sanju Sundaramahalingam; Nicolas Y. Joly; Shangran Xie; Philip St. J. Russell; Bernhard Schmauss. 2021. "Doppler optical frequency domain reflectometry for remote fiber sensing: erratum." Optics Express 29, no. 15: 24193.
Stefan Kefer; Dominik Pape; Gian-Luca Roth; Steffen Hessler; Bernhard Schmauss; Ralf Hellmann. Micromilling-assisted fabrication of monolithic polymer ridge-type waveguides with integrated photonic sensing structures. Optical Materials Express 2021, 11, 2389 .
AMA StyleStefan Kefer, Dominik Pape, Gian-Luca Roth, Steffen Hessler, Bernhard Schmauss, Ralf Hellmann. Micromilling-assisted fabrication of monolithic polymer ridge-type waveguides with integrated photonic sensing structures. Optical Materials Express. 2021; 11 (8):2389.
Chicago/Turabian StyleStefan Kefer; Dominik Pape; Gian-Luca Roth; Steffen Hessler; Bernhard Schmauss; Ralf Hellmann. 2021. "Micromilling-assisted fabrication of monolithic polymer ridge-type waveguides with integrated photonic sensing structures." Optical Materials Express 11, no. 8: 2389.
In this article, we summarize our investigations on optimized 248 nm deep ultraviolet (UV) fabrication of highly stable epoxy polymer Bragg grating sensors and their application for biomedical purposes. Employing m-line spectroscopy, deep UV photosensitivity of cross-linked EpoCore thin films in terms of responding refractive index change is determined to a maximum of Δn = + (1.8 ± 0.2) × 10−3. All-polymer waveguide Bragg gratings are fabricated by direct laser irradiation of lithographic EpoCore strip waveguides on compatible Topas 6017 substrates through standard +1/-1-order phase masks. According near-field simulations of realistic non-ideal phase masks provide insight into UV dose-dependent characteristics of the Bragg grating formation. By means of online monitoring, arising Bragg reflections during grating inscription via beforehand fiber-coupled waveguide samples, an optimum laser parameter set for well-detectable sensor reflection peaks in respect of peak strength, full width at half maximum and grating attenuation are derived. Promising blood analysis applications of optimized epoxy-based Bragg grating sensors are demonstrated in terms of bulk refractive index sensing of whole blood and selective surface refractive index sensing of human serum albumin.
Steffen Hessler; Marieke Rüth; Horst-Dieter Lemke; Bernhard Schmauss; Ralf Hellmann. Deep UV Formation of Long-Term Stable Optical Bragg Gratings in Epoxy Waveguides and Their Biomedical Sensing Potentials. Sensors 2021, 21, 3868 .
AMA StyleSteffen Hessler, Marieke Rüth, Horst-Dieter Lemke, Bernhard Schmauss, Ralf Hellmann. Deep UV Formation of Long-Term Stable Optical Bragg Gratings in Epoxy Waveguides and Their Biomedical Sensing Potentials. Sensors. 2021; 21 (11):3868.
Chicago/Turabian StyleSteffen Hessler; Marieke Rüth; Horst-Dieter Lemke; Bernhard Schmauss; Ralf Hellmann. 2021. "Deep UV Formation of Long-Term Stable Optical Bragg Gratings in Epoxy Waveguides and Their Biomedical Sensing Potentials." Sensors 21, no. 11: 3868.
Coherent optical frequency domain reflectometry has been widely used to locate static reflectors with high spatial resolution. Here, we present a new type of Doppler optical frequency domain reflectometry that offers simultaneous measurement of the position and speed of moving objects. The system is exploited to track optically levitated "flying" particles inside a hollow-core photonic crystal fiber. As an example, we demonstrate distributed temperature sensing with sub-mm-scale spatial resolution and a standard deviation of ∼10°C up to 200°C.
Max Koeppel; Abhinav Sharma; Jasper Podschus; Sanju Sundaramahalingam; Nicolas Y. Joly; Shangran Xie; Philip St. J. Russell; Bernhard Schmauss. Doppler optical frequency domain reflectometry for remote fiber sensing. Optics Express 2021, 29, 14615 -14629.
AMA StyleMax Koeppel, Abhinav Sharma, Jasper Podschus, Sanju Sundaramahalingam, Nicolas Y. Joly, Shangran Xie, Philip St. J. Russell, Bernhard Schmauss. Doppler optical frequency domain reflectometry for remote fiber sensing. Optics Express. 2021; 29 (10):14615-14629.
Chicago/Turabian StyleMax Koeppel; Abhinav Sharma; Jasper Podschus; Sanju Sundaramahalingam; Nicolas Y. Joly; Shangran Xie; Philip St. J. Russell; Bernhard Schmauss. 2021. "Doppler optical frequency domain reflectometry for remote fiber sensing." Optics Express 29, no. 10: 14615-14629.
This contribution demonstrates and discusses electrically tunable polymer planar Bragg gratings based on bulk cyclic olefin copolymers. A lithographic single‐writing‐step method and femtosecond laser reductive sintering of copper(II) oxide nanoparticles are subsequently employed in order to generate buried photonic structures and copper conducting paths on top of the polymer substrate. This way, the necessary number of process steps for fabricating a planar polymer‐based electro‐optical device is greatly reduced. The response of a fully electrified grating structure follows temperature changes, induced by the copper conducting path, with sensitivities up to −31 pm K−1. Dilatometric measurements show that the specimen's behavior is correlated to the situationally reduced thermal expansion of the bulk polymer substrate. In consequence, the tuning response of the photonic platform follows a second order polynomial, whereas a direct current of 30 mA, which correlates to a power consumption of 18.3 mW, leads to a local temperature increase and a residual Bragg wavelength shift of 19.6 K and −547 pm, respectively. Moreover, the outstanding flexibility of the proposed fabrication concept is underlined by demonstrating alternative conducting path geometries, whereas one of the additional designs is adapted to control the spectral width of the Bragg grating's reflection peak.
Stefan Kefer; Kay Bischoff; Gian‐Luca Roth; Julian Haubner; Bernhard Schmauss; Ralf Hellmann. Tunable Bulk Polymer Planar Bragg Gratings Electrified via Femtosecond Laser Reductive Sintering of CuO Nanoparticles. Advanced Optical Materials 2021, 2002203 .
AMA StyleStefan Kefer, Kay Bischoff, Gian‐Luca Roth, Julian Haubner, Bernhard Schmauss, Ralf Hellmann. Tunable Bulk Polymer Planar Bragg Gratings Electrified via Femtosecond Laser Reductive Sintering of CuO Nanoparticles. Advanced Optical Materials. 2021; ():2002203.
Chicago/Turabian StyleStefan Kefer; Kay Bischoff; Gian‐Luca Roth; Julian Haubner; Bernhard Schmauss; Ralf Hellmann. 2021. "Tunable Bulk Polymer Planar Bragg Gratings Electrified via Femtosecond Laser Reductive Sintering of CuO Nanoparticles." Advanced Optical Materials , no. : 2002203.
This contribution demonstrates the functionality of polymer planar Bragg grating (PPBG) sensors integrated into commercial-grade carbon fiber reinforced polymer (CFRP) components. Multiple CFRP specimens are generated by curing a stack of pre-impregnated fibers inside of a heated mechanical press, exposing the polymer sensor to a pressure of 7 bar and a temperature of 120 °C for 2 h. After integration, the sensor still exhibits a strong and evaluable signal. Subsequent flexural experiments reveal a linear response of the integrated sensor’s Bragg wavelength to the CFRP specimen’s maximum deflection. Additional findings demonstrate that the embedded PPBG can be used to detect plastic deformations of a CFRP workpiece, whereas a linear correlation of plastic deformation to the resulting Bragg signal offset is determined. A plausibility check of the obtained results is delivered by a comparison of three-point flexural experiments on bulk CFRP workpieces, without integrated sensors and additional specimens featuring external optical sensors affixed to their surface. It is found that PPBGs based on cyclic olefin copolymers are able to overcome the temperature-related limitations of traditional polymer-based optical sensors and can thus be directly integrated into commercial-grade composites during production.
Stefan Kefer; Theresia Sauer; Steffen Hessler; Michael Kaloudis; Bernhard Schmauss; Ralf Hellmann. Robust Polymer Planar Bragg Grating Sensors Embedded in Commercial-Grade Composites. Polymers 2020, 12, 715 .
AMA StyleStefan Kefer, Theresia Sauer, Steffen Hessler, Michael Kaloudis, Bernhard Schmauss, Ralf Hellmann. Robust Polymer Planar Bragg Grating Sensors Embedded in Commercial-Grade Composites. Polymers. 2020; 12 (3):715.
Chicago/Turabian StyleStefan Kefer; Theresia Sauer; Steffen Hessler; Michael Kaloudis; Bernhard Schmauss; Ralf Hellmann. 2020. "Robust Polymer Planar Bragg Grating Sensors Embedded in Commercial-Grade Composites." Polymers 12, no. 3: 715.
Flexible epoxy waveguide Bragg gratings are fabricated on a low-modulus TPX™ polymethylpentene polyolefin substrate for an easy to manufacture and low-cost optomechanical sensor pad providing exceedingly multipurpose application potentials. Rectangular EpoCore negative resist strip waveguides are formed employing standard UV mask lithography. Highly persistent Bragg gratings are inscribed directly into the channel waveguides by permanently modifying the local refractive indices through a well-defined KrF excimer laser irradiated +1/-1 order phase mask. The reproducible and vastly versatile sensing capabilities of this easy-to-apply optomechanical sensor pad are demonstrated in the form of an optical pickup for acoustic instruments, a broadband optical accelerometer, and a biomedical vital sign sensor monitoring both respiration and pulse at the same time.
Steffen Hessler; Patrick Bott; Stefan Kefer; Bernhard Schmauss; Ralf Hellmann. Multipurpose Polymer Bragg Grating-Based Optomechanical Sensor Pad. Sensors 2019, 19, 4101 .
AMA StyleSteffen Hessler, Patrick Bott, Stefan Kefer, Bernhard Schmauss, Ralf Hellmann. Multipurpose Polymer Bragg Grating-Based Optomechanical Sensor Pad. Sensors. 2019; 19 (19):4101.
Chicago/Turabian StyleSteffen Hessler; Patrick Bott; Stefan Kefer; Bernhard Schmauss; Ralf Hellmann. 2019. "Multipurpose Polymer Bragg Grating-Based Optomechanical Sensor Pad." Sensors 19, no. 19: 4101.
We apply a fast terahertz time-domain spectroscopy (TDS) system based on electronically controlled optical sampling (ECOPS) to contact-free thickness gauging. Our setup achieves a measurement speed of 1600 terahertz pulse traces per second, which—to our knowledge—represents the fastest thickness measurement performed with any terahertz system to-date. Using a silicon wafer as a test sample, we compare data of the ECOPS experiment to results obtained with a conventional terahertz TDS system and a mechanical micrometer gauge. We show that all systems provide consistent results within the measurement accuracy. Moreover, we perform thickness measurements of a rapidly moving sample and characterize the ECOPS setup with respect to time-domain dynamic range, signal-to-noise ratio, and spectral properties.
Milad Yahyapour; Angelika Jahn; Katja Dutzi; Thomas Puppe; Patrick Leisching; Bernhard Schmauss; Nico Vieweg; Anselm Deninger. Fastest Thickness Measurements with a Terahertz Time-Domain System based on Electronically Controlled Optical Sampling. Applied Sciences 2019, 9, 1283 .
AMA StyleMilad Yahyapour, Angelika Jahn, Katja Dutzi, Thomas Puppe, Patrick Leisching, Bernhard Schmauss, Nico Vieweg, Anselm Deninger. Fastest Thickness Measurements with a Terahertz Time-Domain System based on Electronically Controlled Optical Sampling. Applied Sciences. 2019; 9 (7):1283.
Chicago/Turabian StyleMilad Yahyapour; Angelika Jahn; Katja Dutzi; Thomas Puppe; Patrick Leisching; Bernhard Schmauss; Nico Vieweg; Anselm Deninger. 2019. "Fastest Thickness Measurements with a Terahertz Time-Domain System based on Electronically Controlled Optical Sampling." Applied Sciences 9, no. 7: 1283.
In this paper, we present WaterSpy, a project developing an innovative, compact, cost-effective photonic device for pervasive water quality sensing, operating in the mid-IR spectral range. The approach combines the use of advanced Quantum Cascade Lasers (QCLs) employing the Vernier effect, used as light source, with novel, fibre-coupled, fast and sensitive Higher Operation Temperature (HOT) photodetectors, used as sensors. These will be complemented by optimised laser driving and detector electronics, laser modulation and signal conditioning technologies. The paper presents the WaterSpy concept, the requirements elicited, the preliminary architecture design of the device, the use cases in which it will be validated, while highlighting the innovative technologies that contribute to the advancement of the current state of the art.
Nikolaos Doulamis; Athanasios Voulodimos; Anastasios Doulamis; Matthaios Bimpas; Aikaterini Angeli; Nikolaos Bakalos; Alessandro Giusti; Panayiotis Philimis; Antonio Varriale; Alessio Ausili; Sabato D’Auria; George Lampropoulos; Matthias Baer; Bernhard Schmauss; Stephan Freitag; Bernhard Lendl; Krzysztof Młynarczyk; Aleksandra Sosna-Głębska; Artur Trajnerowicz; Jarosław Pawluczyk; Mateusz Żbik; Jacek Kułakowski; Panagiotis Georgiadis; Stéphane Blaser; Nicola Bazzurro. WaterSpy: A High Sensitivity, Portable Photonic Device for Pervasive Water Quality Analysis. Sensors 2018, 19, 33 .
AMA StyleNikolaos Doulamis, Athanasios Voulodimos, Anastasios Doulamis, Matthaios Bimpas, Aikaterini Angeli, Nikolaos Bakalos, Alessandro Giusti, Panayiotis Philimis, Antonio Varriale, Alessio Ausili, Sabato D’Auria, George Lampropoulos, Matthias Baer, Bernhard Schmauss, Stephan Freitag, Bernhard Lendl, Krzysztof Młynarczyk, Aleksandra Sosna-Głębska, Artur Trajnerowicz, Jarosław Pawluczyk, Mateusz Żbik, Jacek Kułakowski, Panagiotis Georgiadis, Stéphane Blaser, Nicola Bazzurro. WaterSpy: A High Sensitivity, Portable Photonic Device for Pervasive Water Quality Analysis. Sensors. 2018; 19 (1):33.
Chicago/Turabian StyleNikolaos Doulamis; Athanasios Voulodimos; Anastasios Doulamis; Matthaios Bimpas; Aikaterini Angeli; Nikolaos Bakalos; Alessandro Giusti; Panayiotis Philimis; Antonio Varriale; Alessio Ausili; Sabato D’Auria; George Lampropoulos; Matthias Baer; Bernhard Schmauss; Stephan Freitag; Bernhard Lendl; Krzysztof Młynarczyk; Aleksandra Sosna-Głębska; Artur Trajnerowicz; Jarosław Pawluczyk; Mateusz Żbik; Jacek Kułakowski; Panagiotis Georgiadis; Stéphane Blaser; Nicola Bazzurro. 2018. "WaterSpy: A High Sensitivity, Portable Photonic Device for Pervasive Water Quality Analysis." Sensors 19, no. 1: 33.
Step-index polymer optical fibers (SI-POFs) are deployed in both sensing and data transmission systems. The optical transmission behavior of these fibers is complex and affected by intrinsic influences like modal dispersion, scattering and attenuation as well as extrinsic influences like the launching condition and the angular sensitivity of the receiver. Since a proper modeling of the transmission behavior is important in order to evaluate the suitability of the fiber for a specific application, we present a novel model for step-index multi-mode fibers (SI-MMFs) which considers all the previously mentioned impacts. Furthermore, the model differentiates scattering and attenuation for propagating rays not only by their propagating angle θ z but also by the skewness θ ϕ . It is therefore possible to distinguish between guided, tunneling and refracted modes. The model uses scatter and attenuation data from previously published measurements of an SI-POF and computes the impulse response of the transmission system which is transferred to the frequency domain to derive the amplitude and phase response. A possible application for SI-POF is the length or strain measurement of the fiber by measuring the phase of a harmonically modulated signal. These sensors rely on a linear relation between the length of the fiber and the phase of the modulated signal. We demonstrate the application of the model by simulating the length measurement error that occurs for these sensors by obtaining the phase response for the corresponding optical transmission system. Furthermore, we will demonstrate the flexibility of the model by varying several influences including the excitation of different mode categories and evaluate the impact on the measurement error. Finally, we compare the simulated length error derived from the model to real data obtained from a cutback measurement. An implementation of the model, which was used for all simulations in this paper, is publicly available.
Thomas Becker; Rainer Engelbrecht; Bernhard Schmauss. Novel Model for the Angle and Skewness Dependent Transmission Behavior of Step-Index Polymer Optical Fiber. Fibers 2018, 6, 65 .
AMA StyleThomas Becker, Rainer Engelbrecht, Bernhard Schmauss. Novel Model for the Angle and Skewness Dependent Transmission Behavior of Step-Index Polymer Optical Fiber. Fibers. 2018; 6 (3):65.
Chicago/Turabian StyleThomas Becker; Rainer Engelbrecht; Bernhard Schmauss. 2018. "Novel Model for the Angle and Skewness Dependent Transmission Behavior of Step-Index Polymer Optical Fiber." Fibers 6, no. 3: 65.
Additive manufacturing has already found broad acceptance in rapid prototyping of machinery and is an emerging technology in many other fields such as radio frequency (RF) engineering, where the advantages of the so-called 3D printing technology overcome limitations of established processes and allow entirely new designs. The ability to create almost arbitrary shapes with high precision has proven very useful for antenna design, for example. Using conductive and dielectric ink, RF transmission lines can be 3D printed directly on uneven surfaces. As for RF structures geometrical dimensions are crucial for the resulting RF properties such as impedance, a technique to measure the distance between the printing nozzle and the substrate is necessary. This turns out to be a challenging task since a small spot size is required and transparent (dielectric) as well as reflective (conductor) materials must be detected while maintaining a mechanically flexible and robust system. We propose a distance measurement system based on coherent optical frequency domain reflectometry to accurately measure this distance. The proposed miniaturized coupling optic uses a gradient-index (GRIN) lens with a diameter of less than 3 mm, can be integrated into a printing head easily and is compatible to standard single-mode fibers. In first experiments, we have achieved very promising results that show a good agreement with (destructive) microscopic measurements. Reflective and transparent surfaces can be detected with μm-accuracy.
Maximilian Deckelmann; Mark Sippel; Konstantin Lomakin; Gerald Gold; Klaus Helmreich; Bernhard Schmauss; Max Koeppel; Stefan Werzinger. Using coherent optical frequency domain reflectometry to assist the additive manufacturing process of structures for radio frequency applications. Reflection, Scattering, and Diffraction from Surfaces VI 2018, 10750, 107500R .
AMA StyleMaximilian Deckelmann, Mark Sippel, Konstantin Lomakin, Gerald Gold, Klaus Helmreich, Bernhard Schmauss, Max Koeppel, Stefan Werzinger. Using coherent optical frequency domain reflectometry to assist the additive manufacturing process of structures for radio frequency applications. Reflection, Scattering, and Diffraction from Surfaces VI. 2018; 10750 ():107500R.
Chicago/Turabian StyleMaximilian Deckelmann; Mark Sippel; Konstantin Lomakin; Gerald Gold; Klaus Helmreich; Bernhard Schmauss; Max Koeppel; Stefan Werzinger. 2018. "Using coherent optical frequency domain reflectometry to assist the additive manufacturing process of structures for radio frequency applications." Reflection, Scattering, and Diffraction from Surfaces VI 10750, no. : 107500R.
Polymer optical fibers (POFs) have been proposed for optical strain sensors due to their large elastic strain range compared to glass optical fibers (GOFs). The phase response of a single-mode polymer optical fiber (SM-POF) is well-known in the literature, and depends on the physical deformation of the fiber as well as the impact on the refractive index of the core. In this paper, we investigate the impact of strain on a step-index polymer optical fiber (SI-POF). In particular, we discuss the responsivity of an optical strain sensor which is based on the phase measurement of an intensity-modulated signal. In comparison to the phase response of an SM-POF, we must take additional influences into account. Firstly, the SI-POF is a multi-mode fiber (MMF). Consequently, we not only consider the strain dependence of the refractive index, but also its dependency on the propagation angle θz. Second, we investigate the phase of an intensity-modulated signal. The development of this modulation phase along the fiber is influenced by modal dispersion, scattering, and attenuation. The modulation phase therefore has no linear dependency on the length of the fiber, even in the unstrained state. For the proper consideration of these effects, we rely on a novel model for step-index multi-mode fibers (SI-MMFs). We expand the model to consider the strain-induced effects, simulate the strain responsivity of the sensor, and compare it to experimental results. This led to the conclusion that the scattering behavior of a SI-POF is strain-dependent, which was further proven by measuring the far field at the end of a SI-POF under different strain conditions.
Thomas Becker; Olaf Ziemann; Rainer Engelbrecht; Bernhard Schmauss. Optical Strain Measurement with Step-Index Polymer Optical Fiber Based on the Phase Measurement of an Intensity-Modulated Signal. Sensors 2018, 18, 2319 .
AMA StyleThomas Becker, Olaf Ziemann, Rainer Engelbrecht, Bernhard Schmauss. Optical Strain Measurement with Step-Index Polymer Optical Fiber Based on the Phase Measurement of an Intensity-Modulated Signal. Sensors. 2018; 18 (7):2319.
Chicago/Turabian StyleThomas Becker; Olaf Ziemann; Rainer Engelbrecht; Bernhard Schmauss. 2018. "Optical Strain Measurement with Step-Index Polymer Optical Fiber Based on the Phase Measurement of an Intensity-Modulated Signal." Sensors 18, no. 7: 2319.
We propose an efficient model-based signal processing approach for optical fiber sensing with fiber Bragg grating (FBG) arrays. A position estimation based on an estimation of distribution algorithm (EDA) and a reflectivity estimation method using a parametric transfer matrix model (TMM) are outlined in detail. The estimation algorithms are evaluated with Monte Carlo simulations and measurement data from an incoherent optical frequency domain reflectometer (iOFDR). The model-based approach outperforms conventional Fourier transform processing, especially near the spatial resolution limit, saving electrical bandwidth and measurement time. The models provide great flexibility and can be easily expanded in complexity to meet different topologies and to include prior knowledge of the sensors. Systematic errors due to crosstalk between gratings caused by multiple reflections and spectral shadowing could be further considered with the TMM to improve the performance of large-scale FBG array sensor systems.
Stefan Werzinger; Darko Zibar; Max Köppel; Bernhard Schmauss. Model-Based Position and Reflectivity Estimation of Fiber Bragg Grating Sensor Arrays. Sensors 2018, 18, 2268 .
AMA StyleStefan Werzinger, Darko Zibar, Max Köppel, Bernhard Schmauss. Model-Based Position and Reflectivity Estimation of Fiber Bragg Grating Sensor Arrays. Sensors. 2018; 18 (7):2268.
Chicago/Turabian StyleStefan Werzinger; Darko Zibar; Max Köppel; Bernhard Schmauss. 2018. "Model-Based Position and Reflectivity Estimation of Fiber Bragg Grating Sensor Arrays." Sensors 18, no. 7: 2268.
Optical temperature sensors offer unique features which make them indispensable for key industries such as the energy sector. However, commercially available systems are usually designed to perform either distributed or distinct hot spot temperature measurements since they are restricted to one measurement principle. We have combined two concepts, fiber Bragg grating (FBG) temperature sensors and Raman-based distributed temperature sensing (DTS), to overcome these limitations. Using a technique called incoherent optical frequency domain reflectometry (IOFDR), it is possible to cascade several FBGs with the same Bragg wavelength in one fiber and simultaneously perform truly distributed Raman temperature measurements. In our lab we have achieved a standard deviation of 2.5K or better at a spatial resolution in the order of 1m with the Raman DTS. We have also carried out a field test in a high-voltage environment with strong magnetic fields where we performed simultaneous Raman and FBG temperature measurements using a single sensor fiber only.
Max Koeppel; Stefan Werzinger; Thomas Ringel; Peter Bechtold; Torsten Thiel; Rainer Engelbrecht; Thomas Bosselmann; Bernhard Schmauss. Combined distributed Raman and Bragg fiber temperature sensing using incoherent optical frequency domain reflectometry. Journal of Sensors and Sensor Systems 2018, 7, 91 -100.
AMA StyleMax Koeppel, Stefan Werzinger, Thomas Ringel, Peter Bechtold, Torsten Thiel, Rainer Engelbrecht, Thomas Bosselmann, Bernhard Schmauss. Combined distributed Raman and Bragg fiber temperature sensing using incoherent optical frequency domain reflectometry. Journal of Sensors and Sensor Systems. 2018; 7 (1):91-100.
Chicago/Turabian StyleMax Koeppel; Stefan Werzinger; Thomas Ringel; Peter Bechtold; Torsten Thiel; Rainer Engelbrecht; Thomas Bosselmann; Bernhard Schmauss. 2018. "Combined distributed Raman and Bragg fiber temperature sensing using incoherent optical frequency domain reflectometry." Journal of Sensors and Sensor Systems 7, no. 1: 91-100.
A method for time and wavelength division multiplexing of fiber Bragg gratings using an electro-optical modulator in a bidirectional configuration is proposed. Broadband frequency conversion enables position measurement while an optical spectrum analyzer provides wavelength resolution.
Stefan Werzinger; Lisa-Sophie Härteis; Max Koeppel; Bernhard Schmauss. Time and Wavelength Division Multiplexing of Fiber Bragg Gratings with Bidirectional Electro-Optical Frequency Conversion. 26th International Conference on Optical Fiber Sensors 2018, ThE19 .
AMA StyleStefan Werzinger, Lisa-Sophie Härteis, Max Koeppel, Bernhard Schmauss. Time and Wavelength Division Multiplexing of Fiber Bragg Gratings with Bidirectional Electro-Optical Frequency Conversion. 26th International Conference on Optical Fiber Sensors. 2018; ():ThE19.
Chicago/Turabian StyleStefan Werzinger; Lisa-Sophie Härteis; Max Koeppel; Bernhard Schmauss. 2018. "Time and Wavelength Division Multiplexing of Fiber Bragg Gratings with Bidirectional Electro-Optical Frequency Conversion." 26th International Conference on Optical Fiber Sensors , no. : ThE19.
In this paper a machine learning method Gaussian process regression (GPR) is applied to directly learn the mapping between the measured spectrum and the temperature. A comparison with other conventional methods is performed and it is shown that the GPR based method gives a better performance in cases with low noise.
Martin S.E. Djurhuus; Stefan Werzinger; Bernhard Schmauss; Anders Clausen; Darko Zibar. Machine learning assisted Fibre Bragg Grating based temperature sensing. 26th International Conference on Optical Fiber Sensors 2018, ThE80 .
AMA StyleMartin S.E. Djurhuus, Stefan Werzinger, Bernhard Schmauss, Anders Clausen, Darko Zibar. Machine learning assisted Fibre Bragg Grating based temperature sensing. 26th International Conference on Optical Fiber Sensors. 2018; ():ThE80.
Chicago/Turabian StyleMartin S.E. Djurhuus; Stefan Werzinger; Bernhard Schmauss; Anders Clausen; Darko Zibar. 2018. "Machine learning assisted Fibre Bragg Grating based temperature sensing." 26th International Conference on Optical Fiber Sensors , no. : ThE80.
Optically trapped “flying particles” inside hollow core photonic crystal fiber (HC-PCF) can be used as multiparameter sensors of, for example, temperature, radiation levels or external electric fields. They represent a new type of optical fiber sensor, offering a spatial resolution that is only limited by the particle size, while being functionally reconfigurable. Here we demonstrate accurate measurement of the axial position of flying particles using incoherent optical frequency domain reflectometry in combination with model-based estimation processing. The approach allows to measure the particle position inside the HC-PCF with a precision of ~140 μm.
Stefan Werzinger; Max Koeppel; Bernhard Schmauss; Dmitry S. Bykov; Richard Zeltner; Andrey Machnev; Shangran Xie; Philip St. J. Russell. High resolution position measurement of “flying particles” inside hollow-core photonic crystal fiber. 2017 IEEE SENSORS 2017, 1 -3.
AMA StyleStefan Werzinger, Max Koeppel, Bernhard Schmauss, Dmitry S. Bykov, Richard Zeltner, Andrey Machnev, Shangran Xie, Philip St. J. Russell. High resolution position measurement of “flying particles” inside hollow-core photonic crystal fiber. 2017 IEEE SENSORS. 2017; ():1-3.
Chicago/Turabian StyleStefan Werzinger; Max Koeppel; Bernhard Schmauss; Dmitry S. Bykov; Richard Zeltner; Andrey Machnev; Shangran Xie; Philip St. J. Russell. 2017. "High resolution position measurement of “flying particles” inside hollow-core photonic crystal fiber." 2017 IEEE SENSORS , no. : 1-3.
Methods from machine learning community are employed for estimating the position of fibre Bragg gratings in an array. Using the conventional methods for position estimation, based on inverse discrete Fourier transform (IDFT), it is required that two-point spatial resolution is less than gratings' spacing. However, we show that by employing statistical inference methods in combination with adaptive gradient algorithm, it is still possible to estimate the grating positions even though this requirement is violated. No prior knowledge of the reflection coefficients is needed as the joint estimation of reflection coefficients and the positions is performed. From the practical point of view, we can demonstrate the reduction of the interrogator's bandwidth by factor of 2. The technique is demonstrated for incoherent optical frequency domain reflectometry (IOFDR). However, the approach is applicable to any other OFDR technique where bandwidth-resolution limitations of IDFT apply.
Darko Zibar; Stefan Werzinger; Bernhard Schmauss. Sub-spatial resolution position estimation for optical fibre sensing applications. 2017 IEEE SENSORS 2017, 1 -3.
AMA StyleDarko Zibar, Stefan Werzinger, Bernhard Schmauss. Sub-spatial resolution position estimation for optical fibre sensing applications. 2017 IEEE SENSORS. 2017; ():1-3.
Chicago/Turabian StyleDarko Zibar; Stefan Werzinger; Bernhard Schmauss. 2017. "Sub-spatial resolution position estimation for optical fibre sensing applications." 2017 IEEE SENSORS , no. : 1-3.
We report on the fabrication of a superstructure Bragg grating in a planar polymer substrate. Based on a twofold illumination process an integrated waveguide and a superstructure Bragg grating are subsequently written into bulk polymethylmethacrylate by UV-induced refractive index modification. The measured reflected spectrum of the superstructure Bragg grating exhibits multiple reflection peaks and is in good agreement with performed standard simulations based on the beam propagation method and coupled mode theory algorithms. By applying a varying tensile load we determine the strain sensitivity to be about 1.10 pm/µε and demonstrate the applicability of the superstructure Bragg grating for strain measurements with redundant sensing signals.
Manuel Rosenberger; Bernhard Schmauss; Ralf Hellmann. UV-Writing of a Superstructure Waveguide Bragg Grating in a Planar Polymer Substrate. Sensors 2017, 17, 1964 .
AMA StyleManuel Rosenberger, Bernhard Schmauss, Ralf Hellmann. UV-Writing of a Superstructure Waveguide Bragg Grating in a Planar Polymer Substrate. Sensors. 2017; 17 (9):1964.
Chicago/Turabian StyleManuel Rosenberger; Bernhard Schmauss; Ralf Hellmann. 2017. "UV-Writing of a Superstructure Waveguide Bragg Grating in a Planar Polymer Substrate." Sensors 17, no. 9: 1964.
We investigate our proposed two stage extended Kalman filtering (EKF) technique for the joint tracking of frequency offset (FO), laser phase noise, fiber nonlinearity as well as amplitude noise. The EKF employed in the first stage coarsely compensates the FO using a set of training data symbols. In the second stage, the employed EKF accomplishes the task of compensating the residual FO, phase noise arising from laser linewidth, fiber nonlinear effects along with simultaneous amplitude noise mitigation. The transmission performance of the proposed two stage EKF has been verified through numerical simulations on polarization multiplexed (PM) 16-quadrature amplitude modulation (QAM) system operating at 28 Gbaud. The results prove that the proposed technique is well tolerant towards the impairments of FO, linear and nonlinear phase noise and amplitude noise even up to ≈3000 km of standard single mode fiber (SSMF) transmission at a launch power of 3 dBm, giving a bit error rate (BER) of ≈2.4e-2 which is the 20% soft decision forward error correction (SD-FEC) threshold. Furthermore, the proposed two stage EKF outperforms a similar two stage approach implemented using linear Kalman filter (LKF) with improved BER.
Lalitha Pakala; Bernhard Schmauss. Two stage extended Kalman filtering for joint compensation of frequency offset, linear and nonlinear phase noise and amplitude noise in coherent QAM systems. 2017 19th International Conference on Transparent Optical Networks (ICTON) 2017, 1 -4.
AMA StyleLalitha Pakala, Bernhard Schmauss. Two stage extended Kalman filtering for joint compensation of frequency offset, linear and nonlinear phase noise and amplitude noise in coherent QAM systems. 2017 19th International Conference on Transparent Optical Networks (ICTON). 2017; ():1-4.
Chicago/Turabian StyleLalitha Pakala; Bernhard Schmauss. 2017. "Two stage extended Kalman filtering for joint compensation of frequency offset, linear and nonlinear phase noise and amplitude noise in coherent QAM systems." 2017 19th International Conference on Transparent Optical Networks (ICTON) , no. : 1-4.