TY - CHAP A1 - Risch, Anna A1 - Hellmann, Ralf T1 - Laser induced modification of GZO thin film T2 - Proceeding XXV microCAD, International scientific conference, 2011, Section K: Material science/Material processing technologies KW - Laser KW - Dünne Schicht Y1 - 2014 SP - 69 EP - 74 ER - TY - CHAP A1 - Rosenberger, Manuel A1 - Belle, Stefan A1 - Hellmann, Ralf T1 - Optical interrogation of chemical and temperature bragg grating sensors using tunable fiber coupled bandpass filter T2 - Proceeding XXV microCAD, International scientific conference, 2011, Section H KW - Bragg-Reflektor Y1 - 2014 SP - 25 EP - 30 ER - TY - CHAP A1 - Rosenberger, Markus A1 - Belle, Stefan A1 - Hellmann, Ralf T1 - Detection of unlabeled DNA hybridization with a planar Bragg Grating Sensor T2 - XXV International MicroCAD Conference – Sensing Technologies, Miskolc (Hungary) KW - Bragg-Reflektor Y1 - 2014 IS - Section R SP - 67 EP - 72 ER - TY - CHAP A1 - Belle, Stefan A1 - Rosenberger, Manuel A1 - Hellmann, Ralf T1 - Optical fibre sensing in the production process and storage of biofuels T2 - Proceeding XXV microCAD, International scientific conference, 2011, Section A KW - Biokraftstoff Y1 - 2014 SP - 21 EP - 26 ER - TY - CHAP A1 - Kalmár, László A1 - Hellmann, Ralf A1 - Régert, Tamás A1 - Varga, Zoltan T1 - Numerical simulation of heat transfer procedure in high power LED modules T2 - Proceedings of the 12th technical and scientific meeting KW - Lumineszenzdiode KW - Wärmeübertragung KW - Simulation Y1 - 2011 SP - 18 EP - 20 ER - TY - CHAP A1 - Heilmann, Eva-Maria A1 - Hellmann, Ralf T1 - High Speed Fibre Laser Material processing of Stainless Steel Tapes Under Tension T2 - XXV International MicroCAD Conference - Material Processing Technologies, Miskolc (Hungary), 21-25 KW - Lasertechnologie Y1 - 2011 ER - TY - CHAP A1 - Hasenstab, Stefan A1 - Adelmann, Benedikt A1 - Hellmann, Ralf T1 - Laser Cutting of Alumina and Aluminum Nitride with a 500 W Single Mode Fiber Laser T2 - XXVII. microCAD International Scientific Conference KW - Laserschneiden KW - Aluminiumoxide Y1 - 2013 ER - TY - CHAP A1 - Sauer, Theresia A1 - Kefer, Stefan A1 - Ruppert, Wolfgang A1 - Hellmann, Ralf A1 - Kaloudis, Michael T1 - Integration of Bragg grating sensors in components made of carbon fiber reinforced polymers T2 - Tagungsband der 20. GMA/ITG-Fachtagung Sensoren und Messsysteme 2019, 25.06.2019 - 26.06.2019, Nürnberg, Deutschland N2 - This contribution discusses the integration of polymer planar Bragg grating sensors (PPBG) into carbon fiber reinforced polymer (CFRP) components. For the first time, it is shown that PPBGs based on cyclic olefin copolymers can be integrated into commercial-grade composites, thereby withstanding the demanding production processes. Pre-impregnated fibers are stacked and partially modified to form a sensor pocket. Afterwards, the CFRP specimen containing the optical sensor is cured in a heated mechanical press for 2 hours at a pressure of 7 bar and a temperature of 120 °C. A subsequent evalutaion of the sensor signal shows a Bragg wavelength shift of 1236 pm and a decline in signal amplitude of -2 dB. Three-point flexural tests of the cured sample reveal a linear behavior of the sensor signal towards external loads. The determined sensitivity in dependence of the CFRP specimen's maximum central deflection is -112 pm/mm, while correlation to the applied force results in a sensitivity of -5 pm/N. KW - Bragg grating sensors KW - carbon fiber reinforced polymers KW - cyclic olefin copolymers KW - structural health monitoring KW - Bragg-Reflektor Y1 - 2019 SN - 978-3-9819376-0-2 U6 - https://doi.org/10.5162/sensoren2019/P3.12 SP - 806 EP - 810 ER - TY - CHAP A1 - Rung, Stefan A1 - Bischoff, Christian A1 - Jäger, Erwin A1 - Umhofer, Udo A1 - Hellmann, Ralf T1 - Laser thin film ablation with multiple beams and tailored beam profiles T2 - Proceedings of SPIE 8967, Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX KW - Thin film KW - Ablation KW - Top-Hat KW - Parallel Processing KW - Beam-Splitter KW - Laserablation KW - Dünnschichttechnik Y1 - 2014 VL - 8967 ER - TY - CHAP A1 - Jäger, Erwin A1 - Rädel, Ulrich A1 - Bischoff, Christian A1 - Umhofer, Udo A1 - Rung, Stefan A1 - Hellmann, Ralf T1 - Laser micromachining – parallel processing with multiple top hat beams T2 - 8th International Conference on Photonic Technologies LANE 2014 KW - Laserbearbeitung Y1 - 2014 ER -