@inproceedings{KeferSchmaussHellmann2023, author = {Kefer, Stefan and Schmauss, Bernhard and Hellmann, Ralf}, title = {Sapphire-Based Planar Bragg Grating Devices}, series = {28th International Conference on Optical Fiber Sensors}, booktitle = {28th International Conference on Optical Fiber Sensors}, isbn = {978-1-957171-30-2}, doi = {10.1364/OFS.2023.W2.4}, year = {2023}, abstract = {This study reports on the long-term stability and the high-temperature capability of sapphire-based photonic crystal waveguides with integrated Bragg gratings. Furthermore, their Bragg grating reflectivity as well as their temperature sensitivity is quantified.}, subject = {Bragg-Reflektor}, language = {en} } @inproceedings{KeferSchmaussHellmann2021, author = {Kefer, Stefan and Schmauss, Bernhard and Hellmann, Ralf}, title = {POLYMER PLANAR BRAGG GRATINGS BASED ON BULK CYCLIC OLEFIN COPOLYMERS: FABRICATION AND FUNCTIONALIZATION}, series = {Proceedings of Student Conference on Sensors, Systems and Measurement 2021}, booktitle = {Proceedings of Student Conference on Sensors, Systems and Measurement 2021}, isbn = {978-80-01-06822-9}, year = {2021}, subject = {Bragg-Reflektor}, language = {en} } @inproceedings{ScheurichBelleHellmannetal.2009, author = {Scheurich, Steffen and Belle, Stefan and Hellmann, Ralf and So, Sik and Sparrow, Ian and Emmerson, Greg}, title = {Planar optical waveguide bragg grating chemical sensor for online process control}, series = {3rd integrated optics - sensors, sensing structures and methodes Korbielow, PL}, booktitle = {3rd integrated optics - sensors, sensing structures and methodes Korbielow, PL}, year = {2009}, subject = {Bragg-Reflektor}, language = {en} } @inproceedings{HuehnleinTschirpkeHellmann2010, author = {H{\"u}hnlein, Kristof and Tschirpke, Katrin and Hellmann, Ralf}, title = {Optimisation of laser cutting using design of experiment - A comparative study of cutting thin ceramic layers using a fibre laser and a CO2 laser}, series = {Physics procedia}, volume = {5}, booktitle = {Physics procedia}, number = {Part B}, issn = {1875-3892}, pages = {243 -- 252}, year = {2010}, subject = {Laserschneiden}, language = {en} } @inproceedings{LutzSchwarzRungetal.2021, author = {Lutz, Christian and Schwarz, Simon and Rung, Stefan and Marx, Jan and Esen, Cemal and Hellmann, Ralf}, title = {Optical system for multi Bessel beam high power ultrashort pulsed laser processing using a spatial light modulator}, series = {Lasers in Manufacturing - LiM 2021}, booktitle = {Lasers in Manufacturing - LiM 2021}, year = {2021}, abstract = {We report on an optical setup for multi Bessel beam processing combining a refractive axicon and a spatial light modulator. Based on their particular beam profile, Bessel beams exhibit various advantages over conventional Gaussian beams for ultrashort pulsed laser processing. Especially for micromachining of transparent materials, applications such as micro-hole drilling or the generation of voids benefit from the increased focal length of the applied Bessel beam. In addition, on account of the significantly increased average output power of industrial ultrashort pulsed lasers over the last years, there is a high demand on multi spot applications for using the available laser power in efficient production processes. Our optical concept combines the dynamic possibilities of beam splitting using spatial light modulator with the benefits of Bessel beams facilitating multi Bessel beam processing.}, subject = {Ultrakurzzeitlaser}, language = {en} } @inproceedings{RosenbergerBelleHellmann2011, author = {Rosenberger, Manuel and Belle, Stefan and Hellmann, Ralf}, title = {Optical interrogation of chemical and temperature bragg grating sensors using tunable fiber coupled bandpass filter}, series = {Proceeding XXV microCAD, International scientific conference, 2011, Section H}, booktitle = {Proceeding XXV microCAD, International scientific conference, 2011, Section H}, pages = {25 -- 30}, year = {2011}, subject = {Bragg-Reflektor}, language = {en} } @inproceedings{RosenbergerBelleHellmann2009, author = {Rosenberger, Manuel and Belle, Stefan and Hellmann, Ralf}, title = {Optical interrogation of bragg grating sensors using tunable fibre based bandpass filter}, series = {Proceedings of the 20st international science conference, Mittweida}, booktitle = {Proceedings of the 20st international science conference, Mittweida}, year = {2009}, subject = {Bragg-Reflektor}, language = {en} } @inproceedings{BelleRosenbergerHellmann2011, author = {Belle, Stefan and Rosenberger, Manuel and Hellmann, Ralf}, title = {Optical fibre sensing in the production process and storage of biofuels}, series = {Proceeding XXV microCAD, International scientific conference, 2011, Section A}, booktitle = {Proceeding XXV microCAD, International scientific conference, 2011, Section A}, pages = {21 -- 26}, year = {2011}, subject = {Biokraftstoff}, language = {en} } @inproceedings{AdelmannNeumeierSchleieretal.2015, author = {Adelmann, Benedikt and Neumeier, Benedikt and Schleier, Max and Wilmann, Eugen and Hellmann, Ralf}, title = {Optical cutting tear detection system for industrial fiber laser based cutting machines}, series = {Lasers in Manufacturing Conference 2015}, booktitle = {Lasers in Manufacturing Conference 2015}, year = {2015}, subject = {Laserschneiden}, language = {en} } @inproceedings{KalmarHellmannRegertetal.2011, author = {Kalm{\´a}r, L{\´a}szl{\´o} and Hellmann, Ralf and R{\´e}gert, Tam{\´a}s and Varga, Zoltan}, title = {Numerical simulation of heat transfer procedure in high power LED modules}, series = {Proceedings of the 12th technical and scientific meeting}, booktitle = {Proceedings of the 12th technical and scientific meeting}, pages = {18 -- 20}, year = {2011}, subject = {Lumineszenzdiode}, language = {en} } @inproceedings{KalmarHellmannRegertetal.2012, author = {Kalm{\´a}r, L{\´a}szl{\´o} and Hellmann, Ralf and R{\´e}gert, Tam{\´a}s and Varga, Zoltan}, title = {Numerical investigation of unsteady heat transport procedure in high power LED module}, series = {GEP}, volume = {2012}, booktitle = {GEP}, number = {1}, pages = {43 -- 46}, year = {2012}, subject = {Lumineszenzdiode}, language = {en} } @inproceedings{KalmarHellmannRegertetal.2012, author = {Kalm{\´a}r, L{\´a}szl{\´o} and Hellmann, Ralf and R{\´e}gert, Tam{\´a}s and Varga, Zoltan}, title = {Numerical investigation of heat transport procedure in high power LED modules}, series = {Proceedings of the XXVI International MicroCAD Conference, Miskolc (Hungary)}, booktitle = {Proceedings of the XXVI International MicroCAD Conference, Miskolc (Hungary)}, pages = {43 -- 46}, year = {2012}, subject = {Lumineszenzdiode}, language = {en} } @inproceedings{KollerHesslerRosenbergeretal.2012, author = {Koller, Georg and Hessler, Steffen and Rosenberger, Manuel and Belle, Stefan and Hellmann, Ralf}, title = {Micro-structured optical waveguide fabrication in PMMA using low frequency reactive ion etching}, series = {Proceedings of the XXVI International MicroCAD Conference - Sensing Technologies, Miskolc (Hungary)}, booktitle = {Proceedings of the XXVI International MicroCAD Conference - Sensing Technologies, Miskolc (Hungary)}, year = {2012}, subject = {Wellenleiter}, language = {en} } @inproceedings{SchwarzRungEsenetal.2020, author = {Schwarz, Simon and Rung, Stefan and Esen, Cemal and Hellmann, Ralf}, title = {Manufacturing of optical elements by non-contact laser processing}, series = {Seventh European Seminar on Precision Optics Manufacturing, Proceedings}, booktitle = {Seventh European Seminar on Precision Optics Manufacturing, Proceedings}, number = {11478}, year = {2020}, subject = {Laserbearbeitung}, language = {en} } @inproceedings{RischHuehnleinKnoelletal.2009, author = {Risch, Anna and H{\"u}hnlein, Kristof and Kn{\"o}ll, J{\"u}rgen and Hellmann, Ralf}, title = {Laserscribing of transparent conductive oxides - a comparative study using nanosecond and picosecond pulsed solid state lasers}, series = {Proceedings of the 20st International Scientific Conference, Mittweida, 2009}, booktitle = {Proceedings of the 20st International Scientific Conference, Mittweida, 2009}, year = {2009}, subject = {Festk{\"o}rperlaser}, language = {en} } @inproceedings{RungBischoffJaegeretal.2014, author = {Rung, Stefan and Bischoff, Christian and J{\"a}ger, Erwin and Umhofer, Udo and Hellmann, Ralf}, title = {Laser thin film ablation with multiple beams and tailored beam profiles}, series = {Proceedings of SPIE 8967, Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX}, volume = {8967}, booktitle = {Proceedings of SPIE 8967, Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX}, year = {2014}, subject = {Laserablation}, language = {en} } @inproceedings{RungHellmann2012, author = {Rung, Stefan and Hellmann, Ralf}, title = {Laser scribing of metallized transparent conductive oxide - A comparative study using top hat and Gaussian beam profiles}, series = {Proceedings of the XXVI International MicroCAD Conference - Material Processing Technologies}, booktitle = {Proceedings of the XXVI International MicroCAD Conference - Material Processing Technologies}, year = {2012}, subject = {Laserbearbeitung}, language = {en} } @inproceedings{JaegerRaedelBischoffetal.2014, author = {J{\"a}ger, Erwin and R{\"a}del, Ulrich and Bischoff, Christian and Umhofer, Udo and Rung, Stefan and Hellmann, Ralf}, title = {Laser micromachining - parallel processing with multiple top hat beams}, series = {8th International Conference on Photonic Technologies LANE 2014}, booktitle = {8th International Conference on Photonic Technologies LANE 2014}, year = {2014}, subject = {Laserbearbeitung}, language = {de} } @inproceedings{RischHellmann2011, author = {Risch, Anna and Hellmann, Ralf}, title = {Laser induced modification of GZO thin film}, series = {Proceeding XXV microCAD, International scientific conference, 2011, Section K: Material science/Material processing technologies}, booktitle = {Proceeding XXV microCAD, International scientific conference, 2011, Section K: Material science/Material processing technologies}, pages = {69 -- 74}, year = {2011}, subject = {Laser}, language = {en} } @inproceedings{HasenstabAdelmannHellmann2013, author = {Hasenstab, Stefan and Adelmann, Benedikt and Hellmann, Ralf}, title = {Laser Cutting of Alumina and Aluminum Nitride with a 500 W Single Mode Fiber Laser}, series = {XXVII. microCAD International Scientific Conference}, booktitle = {XXVII. microCAD International Scientific Conference}, year = {2013}, subject = {Laserschneiden}, language = {en} }