Publikationen
2024
Yang, Y., Bischoff, K., Mücke, D., Esen, C., & Hellmann, R. (2024). UV-ultrashort pulsed laser ablation of fused silica. Journal of Laser Applications, 36(1), doi: 10.2351/7.0001197.
Kefer, S., Limbach, T., Pape, N., Klamt, K., Schmauss, B., & Hellmann, R. (2024). Birefringence in Injection-Molded Cyclic Olefin Copolymer Substrates and Its Impact on Integrated Photonic Structures. Polymers, 16(2), 168, doi: 10.3390/polym16020168.
2023
Franz, D., Yang, Y., Michel, L., Esen, C., & Hellmann, R. (2023). Evaluation of an ultrashort pulsed laser robot system for flexible and large-area micromachining. Journal of Laser Applications, 35(4), doi: 10.2351/7.0001171.
Yang, Y., Franz, D., Esen, C., & Hellmann, R. (2023). Development and comparison of algorithms for beam stabilization in ultrashort pulsed laser equipped on a six-axis robot. Journal of Laser Applications, 35(4), doi: 10.2351/7.0001169.
Bischoff, K., Esen, C., & Hellmann, R. (2023). Preparation of Dispersed Copper (II) Oxide Nanosuspensions as Precursor for Femtosecond Reductive Laser Sintering by High-Energy Ball Milling. Nanomaterials, 13(19), 2693, doi: 10.3390/nano13192693.
Zettl, J., Esen, C., & Hellmann, R. (2023). Fundamental Considerations and Analysis of the Energy Distribution in Laser Turning with Ultrashort Laser Pulses. Micromachines, 14(10), 1838, doi: 10.3390/mi14101838.
Franz, D., Häfner, T., Bischoff, K., Helm, J., Kunz, T., Rung, S., Esen, C., & Hellmann, R. (2023). Picosecond laser microvia drilling of ABF material using MHz burst mode. Materials Research Express, 10(9), 096301, doi: 10.1088/2053-1591/acf7b0.
Lutz, C., Helm, J., Tschirpke, K., Esen, C., & Hellmann, R. (2023). Drilling Sequence Optimization Using Evolutionary Algorithms to Reduce Heat Accumulation for Femtosecond Laser Drilling with Multi-Spot Beam Profiles. Materials, 16(17), 5775, doi: 10.3390/ma16175775.
Gvozdovskyy, I., Bratova, D., Kazantseva, Z., Malyuta, S., Lytvyn, P., Schwarz, S., & Hellmann, R. (2023). Light-controllable hybrid aligning layer based on LIPSS on sapphire surface and PVCN-F film. Journal of Molecular Liquids, 387,122623, doi: 10.1016/j.molliq.2023.122623.
Sommer, D., Esen, C., & Hellmann, R. (2023). Static and Dynamic Mechanical Behaviour of Hybrid-PBF-LB/M-Built and Hot Isostatic Pressed Lattice Structures. Materials, 16(9), 3556, doi: 10.3390/ma16093556.
Yang, Y., Schwarz, S., Esen, C., & Hellmann, R. (2023). Influence of MHz bursts on the ablation efficiency of fused silica. Journal of Laser Applications, 35(2), doi: 10.2351/7.0001002.
Lutz, C., Schwarz, S., Marx, J., Esen, C., & Hellmann, R. (2023). Multi-Bessel Beams Generated by an Axicon and a Spatial Light Modulator for Drilling Applications. Photonics, 10(4), 413, doi: 10.3390/photonics10040413.
Schleier, M., Esen, C., & Hellmann, R. (2023). Evaluation of a Cut Interruption Algorithm for Laser Cutting Steel and Aluminum with a High-Speed Camera. Applied Sciences, 13(7), 4557, doi: 10.3390/app13074557.
Bischoff, K., Kefer, S., Wienke, A., Overmeyer, L., Kaierle, S., Esen, C., & Hellmann, R. (2023). Integration of Bragg gratings in aerosol-jetted polymer optical waveguides for strain monitoring capabilities. Optics Letters, 48(7), 1778-1781, doi: 10.1364/OL.481801.
Kefer, S., Pape, N., Bischoff, K., Schmauss, B., & Hellmann, R. (2023). Lattice-Like Waveguides With Integrated Bragg Gratings in Planar Cyclic Olefin Copolymers. Journal of Lightwave Technology., doi: 10.1109/JLT.2023.3328323.
2022
Adelmann, B., & Hellmann, R. (2022). Mechanical Properties of LPBF-Built Titanium Lattice Structures—A Comparative Study of As-Built and Hot Isostatic Pressed Structures for Medical Implants. Metals, 12(12), 2072, doi: 10.3390/met12122072.
Adelmann, B., Schwiddessen, T., Götzendorfer, B., & Hellmann, R. (2022). Evaluation of SLS 3D-Printed Filter Structures Based on Bionic Manta Structures. Materials, 15(23), 8454, doi: 10.3390/ma15238454.
Schleier, M., Esen, C., & Hellmann, R. (2022). High speed melt flow monitoring and development of an image processing algorithm for laser fusion cutting. Journal of Laser Applications, 34(4), doi: 10.2351/7.0000785.
Adelmann, B., & Hellmann, R. (2022). Function Integration in Additive Manufacturing: Design and Realization of an LPBF Built Compressed Air Motor. Materials, 15(19), 6632, doi: 10.3390/ma15196632.
Kefer, S., Zettl, J., Esen, C., & Hellmann, R. (2022). Femtosecond Laser-Based Micromachining of Rotational-Symmetric Sapphire Workpieces. Materials, 15(18), 6233, doi: 10.3390/ma15186233.
Marx, J., Lutz, C., Hellmann, R., & Esen, C. (2022). Holographic multi-spot generation for ultra-short pulse Bessel beam processing of stainless steel. Procedia CIRP, 111, 648-652, doi: 10.1016/j.procir.2022.08.003.
Rung, S., Häcker, N., & Hellmann, R. (2022). Micromachining of Alumina Using a High-Power Ultrashort-Pulsed Laser. Materials, 15(15), 5328, doi: 10.3390/ma15155328.
Bischoff, K., Mücke, D., Roth, G. L., Esen, C., & Hellmann, R. (2022). UV-Femtosecond-Laser Structuring of Cyclic Olefin Copolymer. Polymers, 14(14), 2962, doi: 10.3390/polym14142962.
Lutz, C., Jung, M., Tschirpke, K., Esen, C., & Hellmann, R. (2022). Optimization of Heat Accumulation during Femtosecond Laser Drilling Borehole Matrices by Using a Simplex Algorithm. Materials, 15(14), 4829, doi: 10.3390/ma15144829.
Franz, D., Häfner, T., Kunz, T., Roth, G. L., Rung, S., Esen, C., & Hellmann, R. (2022). Ultrashort Pulsed Laser Drilling of Printed Circuit Board Materials. Materials, 15(11), 3932, doi: 10.3390/ma15113932.
Voigt, J., Bock, T., Hilpert, U., Hellmann, R., & Moeckel, M. (2022). Increased relative density and characteristic melt pool Signals at the edge in PBF-LB/M. Additive Manufacturing, 57, 102798, doi: 10.1016/j.addma.2022.102798.
Schleier, M., Adelmann, B., Esen, C., & Hellmann, R. (2022). Image processing algorithm for in situ monitoring fiber laser remote cutting by a high-speed camera. Sensors, 22(8), 2863, doi: 10.3390/s22082863.
Kefer, S., Roth, G. L., Zettl, J., Schmauss, B., & Hellmann, R. (2022). Sapphire Photonic Crystal Waveguides with Integrated Bragg Grating Structure. Photonics 9, 234, doi: 10.3390/photonics9040234.
Belle, S., Helfert, S. F., & Hellmann, R. (2022). Hollow Waveguide Arrays as Quarter-and Half-Wave Plates. IEEE Photonics Journal, 14(2), 1-7, doi: 10.1109/JPHOT.2022.3160878.
Belle, S., Helfert, S. F., Kefer, S., Hellmann, R., & Jahns, J. (2022). Space-variant polarization conversion with artificial birefringent metallic elements. Optics Letters, 47(8), 2024-2027, doi: 10.1364/OL.455217.
Franz, D., Häfner, T., Kunz, T., Roth, G. L., Rung, S., Esen, C., & Hellmann, R. (2022). Characterization of a hybrid scanning system comprising acousto-optical deflectors and galvanometer scanners. Applied Physics B, 128(3), 55, doi: 10.1007/s00340-022-07782-2.
Sommer, D., Pape, D., Esen, C., & Hellmann, R. (2022). Tool Wear and Milling Characteristics for Hybrid Additive Manufacturing Combining Laser Powder Bed Fusion and In Situ High-Speed Milling. Materials, 15(3), 1236, doi: 10.3390/ma15031236.
Gvozdovskyy, I., Kazantseva, Z., Schwarz, S., & Hellmann, R. (2022). Influence of Periodic Non-Uniformities of Well-Structured Sapphire Surface by LIPSS on the Alignment of Nematic Liquid Crystal. Nanomaterials, 12(3), 508, doi: 10.3390/nano12030508.
2021
Rung, S., & Hellmann, R. (2021). Laser-induced period surface structures to improve solderability of electrical solder pads. Applied Sciences, 12(1), 80, doi: 10.3390/app12010080.
Sommer, D., Götzendorfer, B., Esen, C., & Hellmann, R. (2021). Design rules for hybrid additive manufacturing combining selective laser melting and micromilling. Materials, 14(19), 5753, doi: 10.3390/ma14195753.
Roth, G. L., Kefer, S., Hessler, S., Esen, C., & Hellmann, R. (2021). Polymer photonic crystal waveguides generated by femtosecond laser. Laser & Photonics Reviews, 15(11), 2100215, doi: 10.1002/lpor.202100215.
Goetzendorfer, B., Kirchgaessner, H., & Hellmann, R. (2021). Tunable, Anisotropic Permeability and Spatial Flow of SLM Manufactured Structures. Materials, 14(18), 5205, doi: 10.3390/ma14185205.
Adelmann, B., & Hellmann, R. (2021). Simultaneous burr and cut interruption detection during laser cutting with neural networks. Sensors, 21(17), 5831, doi: 10.3390/s21175831.
Zettl, J., Klar, M., Rung, S., Esen, C., & Hellmann, R. (2021). Laser turning with ultrashort laser pulses. Journal of Manufacturing Processes, 68, 1562-1568, doi: 10.1016/j.jmapro.2021.06.025.
Schleier, M., Adelmann, B., Esen, C., Glatzel, U., & Hellmann, R. (2021). Development and evaluation of an image processing algorithm for monitoring fiber laser fusion cutting by a high-speed camera. Journal of Laser Applications, 33(3) 032004, doi: 10.2351/7.0000391.
Engdahl, A. K., Belle, S., Wang, T. C., Hellmann, R., Huser, T., & Schüttpelz, M. (2021). Large field-of-view super-resolution optical microscopy based on planar polymer waveguides. ACS Photonics, 8(7), 1944-1950, doi: 10.1021/acsphotonics.1c00914.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2021). Ultrashort pulsed laser backside ablation of fused silica. Optics Express, 29(15), 23477-23486, doi: 10.1364/OE.430516.
Kefer, S., Pape, D., Roth, G. L., Hessler, S., Schmauss, B., & Hellmann, R. (2021). Micromilling-assisted fabrication of monolithic polymer ridge-type waveguides with integrated photonic sensing structures. Optical Materials Express, 11(8), 2389-2400, doi: 10.1364/OME.425778.
Hessler, S., Rüth, M., Lemke, H. D., Schmauss, B., & Hellmann, R. (2021). Deep UV Formation of Long-Term Stable Optical Bragg Gratings in Epoxy Waveguides and Their Biomedical Sensing Potentials. Sensors, 21(11), 3868, doi: 10.3390/s21113868.
Kefer, S., Bischoff, K., Roth, G. L., Haubner, J., Schmauss, B., & Hellmann, R. (2021). Tunable bulk polymer planar Bragg gratings electrified via femtosecond laser reductive sintering of CuO Nanoparticles. Advanced Optical Materials, 9(13), 2002203, doi: 10.1002/adom.202002203.
Zettl, J., Rung, S., Esen, C., & Hellmann, R. (2021). Tangential Laser Turning of Fused Silica Using Ultra-short Laser Pulses. Journal of Laser Micro/Nanoengineering, 16(1), doi: 10.2961/jlmn.2021.01.2008.
Lutz, C., Roth, G. L., Rung, S., Esen, C., & Hellmann, R. (2021). Efficient Ultrashort Pulsed Laser Processing by Dynamic Spatial Light Modulator Beam Shaping for Industrial Use. Journal of Laser Micro/Nanoengineering, 16(1), doi: 10.2961/jlmn.2021.01.2011.
Roth, G. L., Kefer, S., Hessler, S., Esen, C., & Hellmann, R. (2021). Integration of Microfluidic and Photonic Components within Transparent Cyclic Olefin Copolymers by Using fs Laser. Journal of Laser Micro/Nanoengineering, 16(1), doi: 10.2961/jlmn.2021.01.2009.
Schwarz, S., Götzendorfer, B., Rung, S., Esen, C., & Hellmann, R. (2021). Compact beam homogenizer module with laser-fabricated lens-arrays. applied sciences, 11(3), 1018, doi: 10.3390/app11031018.
Adelmann, B., Schleier, M., & Hellmann, R. (2021). Laser cut interruption detection from small images by using convolutional neural network. Sensors, 21(2), 655, doi: 10.3390/s21020655.
2020
Edelmann, A., Dubis, M., & Hellmann, R. (2020). Selective laser melting of patient individualized osteosynthesis plates—Digital to physical process chain. Materials, 13(24), 5786, doi: 10.3390/ma13245786.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2021). Enhanced ablation efficiency using GHz bursts in micromachining fused silica. Optics Letters, 46(2), 282-285, doi: 10.1364/OL.415959.
Edelmann, A., Riedel, L., & Hellmann, R. (2020). Realization of a dental framework by 3D printing in material cobalt-chromium with superior precision and fitting accuracy. Materials, 13(23), 5390, doi: 10.3390/ma13235390.
Belle, S., Goetzendorfer, B., & Hellmann, R. (2020). Challenges in a hybrid fabrication process to generate metallic polarization elements with sub-wavelength dimensions. Materials, 13(22), 5279, doi: 10.3390/ma13225279.
Goetzendorfer, B., Mohr, T., & Hellmann, R. (2020). Hybrid Approaches for Selective Laser Sintering by Building on Dissimilar Materials. Materials, 13(22), 5285, doi: 10.3390/ma13225285.
Hessler, S., Knopf, S., Rommel, M., Girschikofsky, M., Schmauss, B., & Hellmann, R. (2020). Advancing the sensitivity of integrated epoxy-based Bragg grating refractometry by high-index nanolayers. Optics Letters, 45(19), 5510-5513, doi: 10.1364/OL.402768.
Kefer, S., Sauer, T., Hessler, S., Kaloudis, M., & Hellmann, R. (2020). Microstructure-based fiber-to-chip coupling of polymer planar Bragg gratings for harsh environment applications. Sensors, 20(19), 5452, doi: 10.3390/s20195452.
Roth, G. L., Haubner, J., Kefer, S., Esen, C., & Hellmann, R. (2021). Fs-laser based hybrid micromachining for polymer micro-opto electrical systems. Optics and Lasers in Engineering, 137, 106362, doi: 10.1016/j.optlaseng.2020.106362.
Rung, S., Bokan, K., Schwarz, S., Esen, C., & Hellmann, R. (2020). Influence of laser wavelength on the modification of friction between 100Cr6 steel and polytetrafluoroethylene by femtosecond laser-induced periodic surface structures. Journal of Laser Applications, 32(3), doi: 10.2351/7.0000036.
Schwarz, S., Roth, G. L., Rung, S., Esen, C., & Hellmann, R. (2020). Fabrication and evaluation of negative axicons for ultrashort pulsed laser applications. Optics Express, 28(18), 26207-26217, doi: 10.1364/OE.401084.
Kefer, S., Dai, J., Yang, M., Schmauss, B., & Hellmann, R. (2020). Hypersensitive H 2 sensor based on polymer planar Bragg gratings coated with Pt-loaded WO 3-SiO 2. Optics Letters, 45(13), 3601-3604, doi: 10.1364/OL.395341.
Roth, G. L., Hessler, S., Kefer, S., Girschikofsky, M., Esen, C., & Hellmann, R. (2020). Femtosecond laser inscription of waveguides and Bragg gratings in transparent cyclic olefin copolymers. Optics Express, 28(12), 18077-18084, doi: 10.1364/OE.388364.
Röttger, A., Boes, J., Theisen, W., Thiele, M., Esen, C., Edelmann, A., & Hellmann, R. (2020). Microstructure and mechanical properties of 316L austenitic stainless steel processed by different SLM devices. The International Journal of Advanced Manufacturing Technology, 108, 769-783, doi: 10.1007/s00170-020-05371-1.
Kefer, S., Sauer, T., Hessler, S., Kaloudis, M., Schmauss, B., & Hellmann, R. (2020). Robust polymer planar bragg grating sensors embedded in commercial-grade composites. Polymers, 12(3), 715, doi: 10.3390/polym12030715.
Dudutis, J., Pipiras, J., Schwarz, S., Rung, S., Hellmann, R., Račiukaitis, G., & Gečys, P. (2020). Laser-fabricated axicons challenging the conventional optics in glass processing applications. Optics express, 28(4), 5715-5730, doi: 10.1364/OE.377108.
Roth, G. L., Rung, S., Esen, C., & Hellmann, R. (2020). Microchannels inside bulk PMMA generated by femtosecond laser using adaptive beam shaping. Optics Express, 28(4), 5801-5811, doi: 10.1364/OE.384948.
Wüst, P., Edelmann, A., & Hellmann, R. (2020). Areal surface roughness optimization of maraging steel parts produced by hybrid additive manufacturing. Materials, 13(2), 418, doi: 10.3390/ma13020418.
Dudutis, J., Pipiras, J., Schwarz, S., Rung, S., Hellmann, R., Račiukaitis, G., & Gečys, P. (2020). Laser-fabricated axicons for glass dicing applications. Procedia CIRP, 94,957-961, doi: 10.1016/j.procir.2020.09.085.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2020). Rapid fabrication of precise glass axicon arrays by an all laser-based manufacturing technology. Journal of Laser Applications, 32(1), 10.2351/1.5134988.
2019
Hessler, S., Bott, P., Kefer, S., Schmauss, B., & Hellmann, R. (2019). Multipurpose polymer Bragg grating-based optomechanical sensor pad. Sensors, 19(19), 4101, doi: 10.3390/s19194101.
Rung, S., Bokan, K., Kleinwort, F., Schwarz, S., Simon, P., Klein-Wiele, J. H., Esen, C., & Hellmann, R. (2019). Possibilities of dry and lubricated friction modification enabled by different ultrashort laser-based surface structuring methods. Lubricants, 7(5), 43, doi: 10.3390/lubricants7050043.
Roth, G. L., Esen, C., & Hellmann, R. (2019). Circular microchannels inside bulk polymethylmethacrylate generated by femtosecond laser using slit beam shaping. Journal of Laser Applications, 31(2), 022603, doi: 10.2351/1.5096090.
Belle, S., Helfert, S. F., Hellmann, R., & Jahns, J. (2019). Hollow waveguide array with subwavelength dimensions as a space-variant polarization converter. JOSA B, 36(5), D119-D125, doi: 10.1364/JOSAB.36.00D119.
Roth, G. L., Esen, C., & Hellmann, R. (2019). A New Approach to Seal Polymer Microfluidic Devices Using Ultrashort Laser Pulses. Journal of Laser Micro/Nanoengineering, 14(1), doi: 10.2961/jlmn.2019.01.0009.
Trautmann, A., Roth, G. L., Nujiqi, B., Walther, T., & Hellmann, R. (2019). Towards a versatile point-of-care system combining femtosecond laser generated microfluidic channels and direct laser written microneedle arrays. Microsystems & Nanoengineering, 5(1), 6, doi: 10.1038/s41378-019-0046-5.
Girschikofsky, M., Ryvlin, D., Waldvogel, S. R., & Hellmann, R. (2019). Optical sensor for real-time detection of trichlorofluoromethane. Sensors, 19(3), 632, doi: 10.3390/s19030632.
älter als 5 Jahre
Roth, G. L., Esen, C., & Hellmann, R. (2018). Vertical microchannels for microfluidic multilayer interconnections in PMMA. Journal of Laser Micro Nanoengineering, 13(3), 155-159, doi: 10.2961/jlmn.2018.03.0003.
Rung, S., Bokan, K., Rutsch, K., Schwarz, S., Esen, C., & Hellmann, R. (2018). Laser induced periodic surface structures on 100Cr6 steel for modification of friction demonstrated with stribeck test. Journal of Laser Micro/Nanoengineering, 13(3), 160-165, doi: 10.2961/jlmn.2018.03.0004.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2018). Influence of pulse duration on high-precision manufacturing of 3D geometries. Journal of Laser Micro Nanoengineering, 13(3), 292-295, doi: 10.2961/jlmn.2018.03.0025.
Trautmann, A., Götzendorfer, B., Walther, T., & Hellmann, R. (2018). Scaffolds in a shell–a new approach combining one-photon and two-photon polymerization. Optics express, 26(23), 29659-29668, doi: 10.1364/OE.26.029659.
Rung, S., Schwarz, S., Zettl, J., Götzendorfer, B., Esen, C., & Hellmann, R. (2018). Static and dynamic contact angle of water influenced by femtosecond laser based ripple structures on metals. Journal of Laser Micro Nanoengineering, 13(2), 100-104, doi: 10.2961/jlmn.2018.02.0009.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2018). Surface plasmon polariton triggered generation of 1D-low spatial frequency LIPSS on fused silica. Applied Sciences, 8(9), 1624, doi: 10.3390/app8091624.
Förthner, M., Girschikofsky, M., Rumler, M., Stumpf, F., Rommel, M., Hellmann, R., & Frey, L. (2018). One-step nanoimprinted Bragg grating sensor based on hybrid polymers. Sensors and Actuators A: Physical, 283, 298-304, doi: 10.1016/j.sna.2018.09.053.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2018). Homogeneous low spatial frequency LIPSS on dielectric materials generated by beam-shaped femtosecond pulsed laser irradiation. Journal of Laser Micro Nanoengineering, 13(2), 90-94, doi: 10.2961/jlmn.2018.02.0007.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2018). Fabrication of a high-quality axicon by femtosecond laser ablation and CO 2 laser polishing for quasi-Bessel beam generation. Optics Express, 26(18), 23287-23294, doi: .
Ryvlin, D., Girschikofsky, M., Schollmeyer, D., Hellmann, R., & Waldvogel, S. R. (2018). Pollutant Adsorbtion and Detection: Methyl‐Substituted α‐Cyclodextrin as Affinity Material for Storage, Separation, and Detection of Trichlorofluoromethane (Global Challenges 8/2018). Global Challenges, 2(8), 1870184, doi: 10.1002/gch2.201870184.
Ryvlin, D., Girschikofsky, M., Schollmeyer, D., Hellmann, R., & Waldvogel, S. R. (2018). Methyl‐Substituted α‐Cyclodextrin as Affinity Material for Storage, Separation, and Detection of Trichlorofluoromethane. Global Challenges, 2(8), 1800057, doi: 10.1002/gch2.201800057.
Roth, G. L., Esen, C., & Hellmann, R. (2018). Control of femtosecond laser generated microfluidic channels inside poly (methyl methacrylate). Journal of Laser Applications, 30(3), doi: 10.2351/1.5049352.
Rosenberger, M., Kefer, S., Girschikofsky, M., Roth, G. L., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2018). High-temperature stable and sterilizable waveguide Bragg grating in planar cyclo-olefin copolymer. Optics letters, 43(14), 3321-3324, doi: 10.1364/OL.43.003321.
Trautmann, A., Rüth, M., Lemke, H. D., Walther, T., & Hellmann, R. (2018). Two-photon polymerization based large scaffolds for adhesion and proliferation studies of human primary fibroblasts. Optics & Laser Technology, 106, 474-480, doi: 10.1016/j.optlastec.2018.05.008.
Rung, S., Schwarz, S., Götzendorfer, B., Esen, C., & Hellmann, R. (2018). Time dependence of wetting behavior upon applying hierarchic nano-micro periodic surface structures on brass using ultra short laser pulses. Applied Sciences, 8(5), 700, doi: 10.3390/app8050700.
Rosenberger, M., Girschikofsky, M., Förthner, M., Belle, S., Rommel, M., Frey, L., Schmauss, B., & Hellmann, R. (2017). TiO2 surface functionalization of COC based planar waveguide Bragg gratings for refractive index sensing. Journal of Optics, 20(1), 01LT02, doi: 10.1088/2040-8986/aa9bcf.
Hessler, S., Rosenberger, M., Schmauss, B., & Hellmann, R. (2018). Two-dimensional interferometric characterization of laser-induced refractive index profiles in bulk Topas polymer. Optical Materials, 75, 230-235, doi: 10.1016/j.optmat.2017.10.029.
Schleier, M., Adelmann, B., Esen, C., & Hellmann, R. (2017). Cross-correlation-based algorithm for monitoring laser cutting with high-power fiber lasers. IEEE Sensors Journal, 18(4), 1585-1590, doi: 10.1109/JSEN.2017.2783761.
Adelmann, B., & Hellmann, R. (2017). Temperature and stress simulation of 4H-SiC during laser-induced silicidation for ohmic contact generation. Metals, 7(12), 545, doi: 10.3390/met7120545.
Schleier, M., Adelmann, B., Neumeier, B., & Hellmann, R. (2017). Burr formation detector for fiber laser cutting based on a photodiode sensor system. Optics & Laser Technology, 96, 13-17, doi: 10.1016/j.optlastec.2017.04.027.
Girschikofsky, M., Rosenberger, M., Förthner, M., Rommel, M., Frey, L., & Hellmann, R. (2017). Waveguide Bragg gratings in Ormocer® s for temperature sensing. Sensors, 17(11), 2459, doi: 10.3390/s17112459.
Schwarz, S., & Hellmann, R. (2017). Fabrication of cylindrical lenses by combining ultrashort pulsed laser and CO2 laser. Journal of Laser Micro Nanoengineering, 12(2), 76, doi: 10.2961/jlmn.2017.02.0005.
Schwarz, S., Rung, S., & Hellmann, R. (2017). Two-dimensional low spatial frequency laser-induced periodic surface structuring of sapphire. Journal of Laser Micro Nanoengineering, 12(2), 67, doi: 10.2961/jlmn.2017.02.0003.
Rosenberger, M., Schmauss, B., & Hellmann, R. (2017). UV-writing of a superstructure waveguide Bragg grating in a planar polymer substrate. Sensors, 17(9), 1964, doi: 10.3390/s17091964.
Roth, G. L., Esen, C., & Hellmann, R. (2017). Femtosecond laser direct generation of 3D-microfluidic channels inside bulk PMMA. Optics Express, 25(15), 18442-18450, doi: 10.1364/OE.25.018442.
Roth, G. L., Rung, S., & Hellmann, R. (2017). Ultrashort pulse laser micro-welding of cyclo-olefin copolymers. Optics and Lasers in Engineering, 93, 178-181, doi: 10.1016/j.optlaseng.2017.02.006.
Adelmann, B., & Hellmann, R. (2017). A study of SiC decomposition under laser irradiation. Applied Physics A, 123(6), 454, doi: 10.1007/s00339-017-1046-7.
Rosenberger, M., Roth, G. L., Adelmann, B., Schmauss, B., & Hellmann, R. (2017). Temperature referenced planar Bragg grating strain sensor in FS-laser cut COC specimen. IEEE Photonics Technology Letters, 29(11), 885-888, doi: 10.1109/LPT.2017.2693401.
Schwarz, S., Rung, S., & Hellmann, R. (2017). One-dimensional low spatial frequency LIPSS with rotating orientation on fused silica. Applied Surface Science, 411, 113-116, doi: 10.1016/j.apsusc.2017.02.235.
Rosenberger, M., Girschikofsky, M., Schmauss, B., & Hellmann, R. (2016). Fabrication of Bragg gratings in planar PMMA: Impact of UV dosage and thermal annealing. Optics Express, 24(20), 22563-22572, doi: 10.1364/OE.24.022563.
Rosenberger, M., Pauer, H., Girschikofsky, M., Woern, H., Schmauss, B., & Hellmann, R. (2016). Flexible polymer shape sensor based on planar waveguide Bragg gratings. IEEE Photonics Technology Letters, 28(17), 1898-1901, doi: 10.1109/LPT.2016.2574889.
Hessler, S., Rüth, M., Sauvant, C., Lemke, H. D., Schmauss, B., & Hellmann, R. (2017). Hemocompatibility of EpoCore/EpoClad photoresists on COC substrate for optofluidic integrated Bragg sensors. Sensors and Actuators B: Chemical, 239, 916-922, doi: 10.1016/j.snb.2016.08.113.
Girschikofsky, M., Förthner, M., Rommel, M., Frey, L., & Hellmann, R. (2016). Waveguide Bragg gratings in Ormocer hybrid polymers. Optics express, 24(13), 14725-14736, doi: 10.1364/OE.24.014725.
Adelmann, B., & Hellmann, R. (2016). SiC absorption of near-infrared laser radiation at high temperatures. Applied Physics A, 122(7), 642, doi: 10.1007/s00339-016-0173-x.
Rosenberger, M., Schmauss, B., & Hellmann, R. (2016). Influence of the UV dosage on planar Bragg gratings in cyclo-olefin copolymer substrates. Optical Materials Express, 6(6), 2118-2127, doi: 10.1364/OME.6.002118.
Schwarz, S., Rung, S., & Hellmann, R. (2016). Generation of laser-induced periodic surface structures on transparent material-fused silica. Applied Physics Letters, 108(18), doi: 10.1063/1.4948522.
Foerthner, M., Rumler, M., Stumpf, F., Fader, R., Rommel, M., Frey, L., Girschikofsky, M., Belle, S., Hellmann, R., & Klein, J. J. (2016). Hybrid polymers processed by substrate conformal imprint lithography for the fabrication of planar Bragg gratings. Applied Physics A, 122, 1-6, doi: 10.1007/s00339-016-9767-6.
Adelmann, B., Schleier, M., Neumeier, B., & Hellmann, R. (2016). Photodiode-based cutting interruption sensor for near-infrared lasers. Applied optics, 55(7), 1772-1778, doi: 10.1364/AO.55.001772.
Preusch, F., Rung, S., & Hellmann, R. (2016). Influence of polishing orientation on the generation of LIPSS on stainless steel. Journal of Laser Micro Nanoengineering, 11(1), 137, doi: 10.2961/jlmn.2016.01.0025.
Roth, G. L., Rung, S., & Hellmann, R. (2016). Welding of transparent polymers using femtosecond laser. Applied Physics A, 122(2), 86, doi: 10.1007/s00339-016-9605-x.
Adelmann, B., & Hellmann, R. (2016). Numerical and experimental study on flexural strength of laser microstructured alumina. Advances in Ceramic Science and Engineering, 5, 28-34, doi: 10.14355/acse.2016.05.004.
Roth, G. L., Adelmann, B., & Hellmann, R. (2015). Cutting and drilling of SiC semiconductor by fiber laser. Journal of Laser Micro Nanoengineering, 10(3), 279, doi: 10.2961/jlmn.2015.03.0008.
Hessler, S., Rosenberger, M., Belle, S., Schmauss, B., & Hellmann, R. (2015). Influence of chemical polymer composition on integrated waveguide formation induced by excimer laser surface irradiation. Applied Surface Science, 356, 532-538, doi: .
Kutscher, M., Rosenberger, M., Schmauss, B., Meinel, L., Lorenz, U., Ohlsen, K., Hellmann, R., & Germershaus, O. (2016). Surface functionalization allowing repetitive use of optical sensors for real‐time detection of antibody‐bacteria interaction. Journal of Biophotonics, 9(7), 730-737, doi: 10.1002/jbio.201500178.
Adelmann, B., & Hellmann, R. (2015). Fiber Laser Cutting of Alumina Substrates for Electronic Applications Comparison of the Experimentally Determined and Simulated Influence on the Mechanical Strength. Journal of Electrical Engineering, 3, 111-119, doi: 10.17265/2328-2223/2015.03.001.
Adelmann, B., Schleier, M., Neumeier, B., Wilmann, E., & Hellmann, R. (2015). Optical cutting interruption sensor for fiber lasers. Applied Sciences, 5(3), 544-554, doi: 10.3390/app5030544.
Adelmann, B., & Hellmann, R. (2015). Rapid micro hole laser drilling in ceramic substrates using single mode fiber laser. Journal of Materials Processing Technology, 221, 80-86, doi: 10.1016/j.jmatprotec.2015.02.014.
Rosenberger, M., Schmauss, B., & Hellmann, R. (2015). Polymer Planar Bragg Gratings: Rapid fabrication of humidity insensitive Bragg gratings paves the way to multi‐axial strain sensing. Optik & Photonik, 10(3), 48-51, doi: 10.1002/opph.201500020.
Adelmann, B., Ngo, C., & Hellmann, R. (2015). High aspect ratio cutting of metals using water jet guided laser. The International Journal of Advanced Manufacturing Technology, 80, 2053-2060, doi: 10.1007/s00170-015-7161-8.
Rosenberger, M., Eisenbeil, W., Schmauss, B., & Hellmann, R. (2015). Simultaneous 2D strain sensing using polymer planar Bragg gratings. Sensors, 15(2), 4264-4272., doi: .
Preusch, F., Adelmann, B., & Hellmann, R. (2014). Micromachining of AlN and Al2O3 using fiber laser. Micromachines, 5(4), 1051-1060, doi: 10.3390/mi5041082.
Rosenberger, M., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2015). Fabrication and characterization of planar Bragg gratings in TOPAS polymer substrates. Sensors and Actuators A: Physical, 221, 148-153, doi: 10.1016/j.sna.2014.10.040.
Rung, S., Barth, J., & Hellmann, R. (2014). Characterization of laser beam shaping optics based on their ablation geometry of thin films. Micromachines, 5(4), 943-953, doi: 10.3390/mi5040943.
Rosenberger, M., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2014). Humidity-induced effects on polymer planar Bragg gratings. IEEE Photonics Technology Letters, 26(16), 1669-1671, doi: 10.1109/LPT.2014.2330656.
Adelmann, B., & Hellmann, R. (2014). Investigation on Flexural Strength Changes of Alumina Caused by Cutting using Fiber Laser. Journal of Laser Micro/Nanoengineering, 9(2), 153-160, doi: 10.2961/jlmn.2014.02.0014.
Rung, S., Christiansen, A., & Hellmann, R. (2014). Influence of film thickness on laser ablation threshold of transparent conducting oxide thin-films. Applied surface science, 305, 347-351, doi: 10.1016/j.apsusc.2014.03.082.
Rosenberger, M., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2014). Compressive and tensile strain sensing using a polymer planar Bragg grating. Optics express, 22(5), 5483-5490, doi: 10.1364/OE.22.005483.
Girschikofsky, M., Scheurich, S., Belle, S., & Hellmann, R. (2014). Volume contraction of monohydric alcohols interrogated by planar Bragg grating sensor. Optical Engineering, 53(2), 024104-024104., doi: 10.1117/1.OE.53.2.024104.
Adelmann, B., & Hellmann, R. (2013). Investigation on flexural strength during fiber laser cutting of alumina. Physics Procedia, 41, 405-407, doi: 10.1016/j.phpro.2013.03.094.
Rung, S., Rexhepi, M., Bischoff, C., & Hellmann, R. (2013). Laserscribing of thin films using top-hat laser beam profiles. Journal of laser micro nanoengineering, 8(3), 309, doi: 10.2961/jlmn.2013.03.0021.
Adelmann, B., & Hellmann, R. (2013). Process optimization of laser fusion cutting of multilayer stacks of electrical sheets. The International Journal of Advanced Manufacturing Technology, 68, 2693-2701, doi: 10.1007/s00170-013-4884-2.
Girschikofsky, M., Rosenberger, M., Belle, S., Brutschy, M., Waldvogel, S. R., & Hellmann, R. (2013). Allylated cyclodextrins as effective affinity materials in chemical sensing of volatile aromatic hydrocarbons using an optical planar Bragg grating sensor. Analytica chimica acta, 791, 51-59, doi: 10.1016/j.aca.2013.06.042.
Rosenberger, M., Koller, G., Belle, S., Schmauss, B., & Hellmann, R. (2013). Polymer planar Bragg grating sensor for static strain measurements. Optics letters, 38(5), 772-774, doi: 10.1364/OL.38.000772.
Adelmann, B., Hürner, A., Schlegel, T., Bauer, A. J., Frey, L., & Hellmann, R. (2013). Laser alloying nickel on 4H-silicon carbide substrate to generate ohmic contacts. Journal of Laser Micro Nanoengineering, 8(1), 97, doi: 10.2961/jlmn.2013.01.0019.
Heilmann, E. M., Kowalski, T., Teigelkötter, J., & Hellmann, R. (2013). Water Jet Guided Laser Cutting of High Temperature Superconductors. Journal of Laser Micro/Nanoengineering, 8(1), doi: 10.2961/jlmn.2013.01.0014.
Kalmár, L., Hellmann, R., Régert, T., & Vígh, V. (2013). UV LED modulban kialakuló hőátviteli folyamat vizsgálata., doi: 10.36243/fmtu-2013.34.
Hock, K., Adelmann, B., & Hellmann, R. (2012). Comparative study of remote fiber laser and water-jet guided laser cutting of thin metal sheets. Physics Procedia, 39, 225-231, doi: 10.1016/j.phpro.2012.10.033.
Rosenberger, M., Koller, G., Belle, S., Schmauss, B., & Hellmann, R. (2012). Planar Bragg grating in bulk polymethylmethacrylate. Optics express, 20(25), 27288-27296, doi: 10.1364/OE.20.027288.
Girschikofsky, M., Rosenberger, M., Belle, S., Brutschy, M., Waldvogel, S. R., & Hellmann, R. (2012). Highly sensitive detection of naphthalene in solvent vapor using a functionalized PBG refractive index sensor. Sensors, 12(2), 2018-2025, doi: 10.3390/s120202018.
Bischoff, C., Hellmann, R., & Rung, S. (2012). Efficient Micromachining of Thin Films with Nanosecond Lasers: Beam shaping optics improve process quality and enhance throughput. Laser Technik Journal, 9(5), 15-20, doi: 10.1002/latj.201290062.
Girschikofsky, M., Rosenberger, M., Belle, S., Brutschy, M., Waldvogel, S. R., & Hellmann, R. (2012). Optical planar Bragg grating sensor for real-time detection of benzene, toluene and xylene in solvent vapour. Sensors and Actuators B: Chemical, 171, 338-342, doi: 10.1016/j.snb.2012.04.046.
Adelmann, B., & Hellmann, R. (2011). Fast laser cutting optimization algorithm. Physics Procedia, 12, 591-598, doi: 10.1016/j.phpro.2011.03.075.
Risch, A., & Hellmann, R. (2011). Picosecond laser patterning of ITO thin films. Physics Procedia, 12, 133-140, doi: 10.1016/j.phpro.2011.03.115.
Risch, A., & Hellmann, R. (2011). Laser scribing of gallium doped zinc oxide thin films using picosecond laser. Applied Surface Science, 258(5), 1849-1853, doi: 10.1016/j.apsusc.2011.10.060.
Heilmann, E. M., Seidl, A., & Hellmann, R. (2011). Water Jet Guided Laser Cutting of Silicon Thin Films Using 515nm Disk Laser. Journal of Laser Micro/Nanoengineering, 6(2), doi: 10.2961/jlmn.2011.02.0013.
Amrhein, F., Kehrer, M., Schreck, T., Bochtler, U., Hellmann, R., & Kaloudis, M. (2011). More efficient curing of UV sensitive mounting materials. Practical metallography, 48(7), 356-364, doi: 10.3139/147.110126.
Amrhein, F., Kehrer, M., Schreck, T., Bochtler, U., Hellmann, R., & Kaloudis, M. (2011). Effizienteres Aushärten UV-sensitiver Einbett-Materialien. Practical Metallography, 48(7), 356-364, doi: 10.3139/147.110126.
Amrhein, F., Kehrer, M., Schreck, T., Bochtler, U., Hellmann, R., & Kaloudis, M. (2011). Schnelle Aushärtung auch im Schatten: UV-LED-Bestrahlung von Vergussmaterial. adhäsion KLEBEN & DICHTEN, 55, 38-41, doi: 10.1365/s35145-011-0032-z.
Hühnlein, K., Tschirpke, K., & Hellmann, R. (2010). Optimization of laser cutting processes using design of experiments. Physics Procedia, 5, 243-252, doi: 10.1016/j.phpro.2010.08.050.
Euteneuer, A., Hellmann, R., Göbel, E., Shevel, S., Vozny, V., Vytrykhivsky, M., Petrie, W., & Klingshirn, C. (1998). The effect of disorder on the exciton dynamics in cation-substituted ZnxCd1− xS mixed crystals. Journal of crystal growth, 184, 1081-1084, doi: 10.1016/S0022-0248(98)80226-1.
Shevel, S., Euteneuer, A., Hellmann, R., Göbel, E. O., Vozny, V., Vytrykhivsky, M., Petri, W., & Klingshirn, C. (1998). Effect of Disorder on Exciton Dynamics in Cation‐Substituted ZnxCd1—xS Mixed Crystals. physica status solidi (b), 205(2), 667-681, doi: 10.1002/(SICI)1521-3951(199802)205:2<667::AID-PSSB667>3.0.CO;2-2.
Yakovlev, D. R., Kavokin, K. V., Merkulov, I. A., Mackh, G., Ossau, W., Hellmann, R., Waag, A., & Landwehr, G. (1997). Picosecond dynamics of magnetic polarons governed by energy transfer to the Zeeman reservoir. Physical Review B, 56(15), 9782, doi: 10.1103/PhysRevB.56.9782.
Cundiff, S. T., Hellmann, R., Koch, M., Mackh, G., Waag, A., Landwehr, G., Know, W. H., & Göbel, E. O. (1996). Excitonic dephasing in semimagnetic semiconductors. JOSA B, 13(6), 1263-1267, doi: 10.1364/JOSAB.13.001263.
Hellmann, R., Euteneuer, A., Göbel, E. O., Mackh, G., Yakovlev, D. R., Waag, A., & Landwehr, G. (1996). Dynamics of exciton magnetic polarons in Cd1− xMnxTeCd1− x− yMnxMgyTe quantum wells. Journal of crystal growth, 159(1-4), 976-979, doi: 10.1016/0022-0248(95)00735-0.
Mackh, G., Ossau, W., Yakovlev, D. R., Landwehr, G., Hellmann, R., Göbel, E. O., Wojtowicz, T., Karcewski, G., & Kossut, J. (1995). Exciton magnetic polarons in CdTe/Cd1− xMnxTe quantum wells with high manganese contents. Solid state communications, 96(5), 297-304, doi: 10.1016/0038-1098(95)80102-2.
Mackh, G., Ossau, W., Yakovlev, D. R., Landwehr, G., Hellmann, R., Göbel, E. O., Wojtowicz, T., Karczewski, G., & Kossut, J. (1995). Exciton magnetic polarons in CdTe/Cd1− xMnxTe quantum wells with high manganese contents. Solid state communications, 96(5), 297-304, doi: 10.1016/0038-1098(95)80102-2.
Hellmann, R., Euteneuer, A., Hense, S. G., Feldmann, J., Thomas, P., Göbel, E. O., Yakovlev, D. R., Waag, A., & Landwehr, G. (1995). Low-temperature anti-Stokes luminescence mediated by disorder in semiconductor quantum-well structures. Physical Review B, 51(24), 18053, doi: 10.1103/PhysRevB.51.18053.
Koch, M., Hellmann, R., Bastian, G., Feldmann, J., Göbel, E. O., & Dawson, P. (1995). Enhanced energy and phase relaxation of excitons in the presence of bare electrons. Physical Review B, 51(19), 13887, doi: .
Koch, M., Bastian, G., Hellmann, R., Feldmann, J., Göbel, E. O., & Dawson, P. (1995). Exciton scattering with bare electrons. physica status solidi (b), 188(1), 485-492, doi: 10.1002/pssb.2221880146.
Hellmann, R., Cundiff, S. T., Koch, M., Feldmann, J., Göbel, E. O., Kuhn-Heinrich, B., Yakovlev, D. R., Waag, A., & Landwehr, G. (1994). Exciton dynamics in disordered quantum wells: Localized and delocalized regimes. Physical Review B, 50(19), 14651, doi: 10.1103/PhysRevB.50.14651.
Mackh, G., Hilpert, M., Yakovlev, D. R., Ossau, W., Heinke, H., Litz, T., Fischer, F., Waag, A., Landwehr, G., Hellmann, R., & Göbel, E. O. (1994). Exciton magnetic polarons in the semimagnetic alloys Cd 1− x− y Mn x Mg y Te. Physical Review B, 50(19), 14069, doi: 10.1103/PhysRevB.50.14069.
Ossau, W., Zehnder, U., Kuhn-Heinrich, B., Waag, A., Litz, T., Landwehr, G., Hellmann, R., & Göbel, E. O. (1994). Cd1-xMgxTe: a new promising barrier material to CdTe based heterostructures. Superlattices and microstructures, 16(1), 5-10., doi: 10.1006/spmi.1994.1099.
Kochereshko, V. P., Pozina, G. R., Ivchenko, E. L., Yakovlev, D. R., Waag, A., Ossau, W., Landwehr, G., Hellmann, R., & Göbel, E. O. (1994). Giant exciton resonance reflectance in Bragg MQW structures. Superlattices and microstructures, 15(4), 471-473, doi: 10.1006/spmi.1994.1090.
Mackh, G., Ossau, W., Yakovlev, D. R., Waag, A., Landwehr, G., Hellmann, R., & Göbel, E. O. (1994). Localized exciton magnetic polarons in Cd 1− x Mn x Te. Physical Review B, 49(15), 10248, doi: 10.1103/PhysRevB.49.10248.
Hellmann, R., Koch, M., Feldmann, J., Cundiff, S. T., Göbel, E. O., Yakovlev, D. R., Waag, A., & Landwehr, G. (1994). Dephasing of excitons in a CdTe/Cd0. 86Mn0. 14Te multiple quantum well. Journal of crystal growth, 138(1-4), 791-795, doi: 10.1016/0022-0248(94)90908-3.
Koch, M., Hellmann, R., Cundiff, S. T., Feldmann, J., Goebel, E. O., Yakovlev, D. R., Waag, A., & Landwehr, G. (1994) Excitonic quantum beats in CdTeCd1−xMnxTe Quantum wellsSolid State Communications, 88(7) 515, doi: 10.1016/0038-1098(93)90040-T.
Hellmann, R., Pohlmann, A., Göbel, E. O., Yakovlev, D. R., Waag, A., Bicknell‐Tassius, R. N., & Landwehr, G. (1993). Time resolved photoluminescence studies of perpendicular transport in CdTe/Cd1− x Mn x Te short‐period superlattices. Journal of applied physics, 74(8), 5272-5274, doi: 10.1063/1.354270.
Hellmann, R., Koch, M., Feldmann, J., Cundiff, S. T., Göbel, E. O., Yakovlev, D. R., Waag, A., & Landwehr, G. (1993). Homogeneous linewidth of excitons in semimagnetic CdTe/Cd 1− x Mn x Te multiple quantum wells. Physical Review B, 48(4), 2847, doi: 10.1103/PhysRevB.48.2847.
Polhmann, A., Hellmann, R., Göbel, E. O., Yakovlev, D. R., Ossau, W., Waag, A., Bicknell-Tassius, R. N., & Landwehr, G. (1992). Exciton lifetimes in CdTe/CdMnTe single quantum wells. Applied physics letters, 61(24), 2929-2931, doi: 10.1063/1.108025.
2024
Lutz, C., Schwarz, S., Marx, J., Esen, C., & Hellmann, R. (2024, March). Combination of an axicon and a spatial light modulator for the generation of multiBessel beams for microdrilling using ultrashort pulsed laser. In Laser-based Micro-and Nanoprocessing XVIII (Vol. 12873, pp. 290-296). SPIE, doi: 10.1117/12.3000946.
Zettl, J., Bischoff, K., Esen, C., & Hellmann, R. (2024, March). Laser turning of PMMA with ultrashort laser pulses using UV and IR. In Laser-based Micro-and Nanoprocessing XVIII (Vol. 12873, pp. 297-304). SPIE, doi: 10.1117/12.3001013.
Lutz, C., Sommerhuber, R., Kettner, M., Esen, C., & Hellmann, R. (2024, March). Towards process control by detecting acoustic emissions during ultrashort pulsed laser ablation of multilayer materials. In Laser-based Micro-and Nanoprocessing XVIII (Vol. 12873, pp. 227-232). SPIE, doi: 10.1117/12.3000954.
Zettl, J., Esen, C., & Hellmann, R. (2024, March). Intensity distribution on cylindrical surfaces in ultrashort pulse laser turning. In Laser-based Micro-and Nanoprocessing XVIII (Vol. 12873, pp. 216-226). SPIE, doi: 10.1117/12.3000995.
Sommer, D., Hornung, S., Esen, C., & Hellmann, R. (2024, March). Optimization of mechanical properties of additive manufactured IN 718 parts combining LPBF and in-situ high-speed milling. In Laser 3D Manufacturing XI (Vol. 12876, pp. 117-125). SPIE, doi: 10.1117/12.3000952.
Sommer, D., Safi, A., Esen, C., & Hellmann, R. (2024, March). Additive manufacturing of Nickel-based superalloy: optimization of surface roughness using integrated high-speed milling. In Laser 3D Manufacturing XI (Vol. 12876, pp. 185-193). SPIE, doi: 10.1117/12.3000972.
Lutz, C., Helm, J., Esen, C., & Hellmann, R. (2024, March). Computational optimization of borehole sequences for the reduction of heat accumulation in drilling processes using ultrashort pulse lasers. In Laser-based Micro-and Nanoprocessing XVIII (Vol. 12873, pp. 278-289). SPIE, doi: 10.1117/12.3000930.
2023
Wang, J., Hu, W., Yang, M., Kefer, S., & Hellmann, R. (2023, November). Hydrogen sensor based on PPBG coated with porous Pt/WO3. In Advanced Sensor Systems and Applications XIII (Vol. 12771, pp. 158-161). SPIE., doi: 10.1117/12.2683838.
Kefer, S., Pape, N., Schmauss, B., & Hellmann, R. (2023, November). Fabrication of Lattice-Like Waveguides in Planar Cyclic Olefin Copolymers. In Optical Fiber Sensors (pp. Th6-69). Optica Publishing Group, doi: 10.1364/OFS.2023.Th6.69.
Kefer, S., Schmauss, B., & Hellmann, R. (2023, November). Sapphire-Based Planar Bragg Grating Devices. In Optical Fiber Sensors (pp. W2-4). Optica Publishing Group., doi: 10.1364/OFS.2023.W2.4.
Bischoff, K., Mücke, D., Esen, C., & Hellmann, R. (2023). UV-Femtosecond-Laser Structuring of Silicon Carbide. In International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2023.
Bischoff, K., Esen, C., & Hellmann, R. (2023). Acceleration of Femtosecond Reductive Laser Sintering of Copper (II) Oxide for Conductive Copper Patterns on Cyclic Olefin Copolymers. In International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2023.
Franz, D., Mücke, D., Kunz, T., Rung, S., Esen, C., & Hellmann, R. (2023). UV picosecond laser drilling of ABF film material for printed circuit boards using laser burst mode and beam shaping. In International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2023.
Marx, J., Esen, C., Lutz, C., Hellmann, R., & Ostendorf, A. (2023). Holographic tuning of physical axicons. In Lasers in Manufacturing 2023
Kefer, S., Zettl, J., Schmauss, B., Esen, C., & Hellmann, R. (2023, March). High-precision micromachining of sapphire towards optical waveguiding structures using femtosecond lasers. In Laser-based Micro-and Nanoprocessing XVII (Vol. 12409, pp. 231-239). SPIE, doi: 10.1117/12.2648758.
Kefer, S., Pape, N., Gries, N., Roth, G. L., Schmauss, B., & Hellmann, R. (2023, March). Towards pressure sensors based on polymer planar Bragg gratings. In Organic Photonic Materials and Devices XXV (Vol. 12418, pp. 65-70). SPIE, doi: 10.1117/12.2648723.
2022
Zhou, Y., Hu, W., Ye, Y., Wang, J., Dai, J., Yang, M., & Kefer, S. & Hellmann, R., (2022, December). Hydrogen sensor based on planar polymer Bragg grating coated with Pd/Ni composite film. In Advanced Sensor Systems and Applications XII (Vol. 12321, pp. 168-171). SPIE., doi: 10.1117/12.2643877.
Schleier, M., Esen, C., & Hellmann, R. (2022). High speed melt flow monitoring and development of an image processing algorithm for laser fusion cutting In International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2022, doi: 10.2351/7.0000785.
Marx, J., Lutz, C., Hellmann, R., & Esen, C. (2022). Holographic multi-spot generation for ultra-short pulse Bessel beam processing of stainless steel. In 12th CIRP Conference on Photonic Technologies (LANE) 2022, doi: 10.1016/j.procir.2022.08.003.
2021
Adelmann, B., Abb, M., & Hellmann, R. (2021, November). Comparative study of cell growth and cellular adhesion on Ti-6Al-4V surfaces made by Selective Laser Melting followed by different surface post processing steps. In IOP Conference Series: Materials Science and Engineering (Vol. 1135, No. 1, p. 012028). IOP Publishing, doi: 10.1088/1757-899X/1135/1/012028.
Rung, S., Häcker, N., & Hellmann, R. (2021, November). Thermal imaging of high power ultrashort pulse laser ablation of alumina towards temperature optimized micro machining strategies. In IOP Conference Series: Materials Science and Engineering (Vol. 1135, No. 1, p. 012027). IOP Publishing, doi: 10.1088/1757-899X/1135/1/012027.
Lutz, C., Esen, C., & Hellmann, R. (2021, November). Ultrashort-pulsed laser processing with spatial and temporal beam shaping using a spatial light modulator and burst modes. In IOP Conference Series: Materials Science and Engineering (Vol. 1135, No. 1, p. 012026). IOP Publishing, doi: 10.1088/1757-899X/1135/1/012026.
Schwarz, S., Esen, C., & Hellmann, R. (2021). Präzise Mikromaterialbearbeitung von Gläsern mittels ultrakurz gepulster Laserstrahlung. In 11. Workshop Laserbearbeitung von Glaswerkstoffen.
Zettl, J., Bischoff, C., Rung, S., Esen, C., Lasagni, A. F., & Hellmann, R. (2021). Laser turning using ultra-short laser pulses and intensity distribution techniques. In Lasers in Manufacturing 2021.
Franz, D., Roth, G. L., Rung, S., Esen, C., & Hellmann, R. (2021). Superimposed beam deflection using acousto-optical deflectors in combination with a galvanometer scanner. In Lasers in Manufacturing 2021.
Lutz, C., Schwarz, S., Rung, S., Marx, J., Esen, C., & Hellmann, R. (2021). Optical system for multi Bessel beam high power ultrashort pulsed laser processing using a spatial light modulator. In Lasers in Manufacturing 2021.
Schleier, M., Adelmann, B., Esen, C., Glatzel, U., & Hellmann, R. (2021). Monitoring of the melt pool for fiber laser cutting using a high-speed camera. In Lasers in Manufacturing 2021.
Kefer, S., Roth, F., Kaloudis, M., Schmauss, B., & Hellmann, R. (2021). Monitoring of Composite Bicycle Components Using Polymer Planar Bragg Gratings. In SMSI 2021 Sensor and Measurement Science International, doi: 10.5162/SMSI2021/B9.2.
Belle, S., Kefer, S., Waldvogel, S. R., & Hellmann, R. (2021). Planar Bragg Grating Sensors Functionalized with Cyclodextrins for Trichlorofluoromethane Sensing. In SMSI 2021 Sensor and Measurement Science International, doi: 10.5162/SMSI2021/B3.1.
Dudutis, J., Pipiras, J., Schwarz, S., Rung, S., Hellmann, R., Račiukaitis, G., & Gečys, P. (2021, March). Laser-fabricated axicons as an alternative to conventional optics for glass dicing. In Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XXVI (Vol. 11673, pp. 52-60). SPIE, doi: 10.1117/12.2574836.
2020
Dudutis, J., Pipiras, J., Schwarz, S., Rung, S., Hellmann, R., Račiukaitis, G., & Gečys, P. (2020). Laser-fabricated axicons for glass dicing applications. In 11th CIRP Conference on Photonic Technologies, doi: 10.1016/j.procir.2020.09.085.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2020). UKP-Prozess mit anschließendem CO2-Laserpolieren zur Fertigung komplexer Optiken. In 10. Workshop Laserbearbeitung von Glaswerkstoffen.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2020). Current results on laser-based production of complex optics in glass. In 10. Wetzlarer Herbsttagung" Moderne Optikfertigung", 29.-30. September 2020, Wetzlar.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2020, July). Manufacturing of optical elements by non-contact laser processing. In Seventh European Seminar on Precision Optics Manufacturing (Vol. 11478, pp. 11-17). SPIE, doi: 10.1117/12.2564713.
Kefer, S., Rosenberger, M., Hessler, S., Girschikofsky, M., Belle, S., Roth, G. L., Schmauss, B., & Hellmann, R. (2019, December). Fabrication and applications of polymer planar Bragg grating sensors based on cyclic olefin copolymers. In 2019 Photonics & Electromagnetics Research Symposium-Fall (PIERS-Fall) (pp. 647-655). IEEE, doi: 10.1109/PIERS-Fall48861.2019.9021801.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2020, March). All laser-based fabrication of optical elements. In Frontiers in Ultrafast Optics: Biomedical, Scientific, and Industrial Applications XX (Vol. 11270, pp. 114-122). SPIE, doi: 10.1117/12.2543667.
Roth, G. L., Esen, C., & Hellmann, R. (2020, March). Internal micro structuring of transparent optical polymers by fs laser. In Laser-based Micro-and Nanoprocessing XIV (Vol. 11268, pp. 322-330). SPIE., doi: 10.1117/12.2543487.
Belle, S., Helfert, S. F., Hellmann, R., & Jahns, J. (2020, February). Space-variant quarter-and half-wave plates fabricated by combining 3D laser direct writing and electroplating. In Advanced Fabrication Technologies for Micro/Nano Optics and Photonics XIII (Vol. 11292, pp. 106-115). SPIE, doi: 10.1117/12.2543560.
2019
Girschikofsky, M., Ryvlin, D., Hessler, S., Waldvogel, S. R., & Hellmann, R. (2019, November). Planar optical sensor for trichlorofluoromethane. In SPIE Future Sensing Technologies (Vol. 11197, pp. 48-53). SPIE, doi: 10.1117/12.2542013.
Hessler, S., Bott, P., Kefer, S., Girschikofsky, M., Schmauß, B., & Hellmann, R. (2019, November). Enhanced seismic sensing based on epoxy waveguide Bragg gratings. In SPIE Future Sensing Technologies (Vol. 11197, pp. 93-97). SPIE, doi: 10.1117/12.2542646.
Flachs, D., Emmerich, F., Roth, G. L., Hellmann, R., & Thielemann, C. (2019, November). Laser-bonding of FEP/FEP interfaces for a flexible manufacturing process of ferroelectrets. In Journal of Physics: Conference Series(Vol. 1407, No. 1, p. 012107). IOP Publishing, doi: 10.1088/1742-6596/1407/1/012107.
Roth, G. L., Wolf, B., Esen, C., & Hellmann, R. (2019). Generation of internal 3D microfluidic architectures in polymers by fs laser processing. In Lasers in Manufacturing 2019.
Sauer, T., Kefer, S., Ruppert, W., Hellmann, R., & Kaloudis, M. (2019). Integration of Bragg grating sensors in components made of carbon fiber reinforced polymers. In Tagungsband der 20. GMA/ITG-Fachtagung Sensoren und Messsysteme 2019, 25.06. 2019-26.06. 2019, Nürnberg, Deutschland (pp. 806-810), doi: 10.5162/sensoren2019/P3.12.
Dudutis, J., Pipiras, J., Schwarz, S., Rung, S., Hellmann, R., & Gečys, P. (2019). Bessel beam formation with all laser fabricated axicon-case of glass dicing applications. In COLA 2019, 15th International Conference on Laser Ablation.
Dudutis, J., Pipiras, J., Schwarz, S., Rung, S., Hellmann, R., Račiukaitis, G., & Gečys, P. (2019). Glass cutting by oblate-tip axicon-generated Bessel-Gaussian beams. In Open Readings, 63rd International Conference for Students of Physics and Natural Sciences.
älter als 5 Jahre
Girschikofsky, M., Ryvlin, D., Waldvogel, S. R., & Hellmann, R. (2018, November). Planar Bragg Grating Sensor for the Detection of CFC-11. In Optics and Photonics for Energy and the Environment (pp. ET5A-5). Optica Publishing Group, doi: 10.1364/EE.2018.ET5A.5.
Schwarz, S., Esen, C., & Hellmann, R. (2018). CO2 laser polishing of femtosecond shaped micro-optical components. In 3rd Conference on Laser Polishing LaP 2018.
Adelmann, B., Lutz, C., & Hellmann, R. (2018, August). Investigation on shear and tensile strength of laser welded electrical sheet stacks. In 2018 IEEE 14th International Conference on Automation Science and Engineering (CASE) (pp. 565-569). IEEE, doi: 10.1109/COASE.2018.8560442.
Roth, G. L., Esen, C., & Hellmann, R. (2018). Circular microchannels inside bulk polymethylmethacrylate generated by femtosecond laser using slit beam shaping. In International Congress on Applications of Lasers & Electro-Optics (ICALEO) 2018, doi: 10.2351/1.5096090.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2018). Axicon fabrication with ultrashort and CO2 laser. In LPM2018 The 19th International Symposium on Laser Precision Microfabrication.
Schwarz, S., Esen, C., & Hellmann, R. (2018). Homogeneous low spatial frequency LIPSS on dielectrics generated by beam-shaped femtosecond pulsed laser irradiation. In LPM2018 The 19th International Symposium on Laser Precision Microfabrication.
Roth, G. L., Esen, C., & Hellmann, R. (2018). A New Approach to Seal Polymer Microfluidic Devices Using Ultrashort Laser Pulses. In LPM2018 The 19th International Symposium on Laser Precision Microfabrication.
Schwarz, S., Rung, S., Esen, C., & Hellmann, R. (2018). Influence of pulse duration on high-precision manufacturing of 3D geometries. In LPM2018 The 19th International Symposium on Laser Precision Microfabrication.
Rung, S., Schwarz, S., Zettl, J., Götzendorfer, B., Esen, C., & Hellmann, R. (2018). Static and dynamic contact angle of water influenced by femtosecond laser based ripple structures on metals. In LPM2018 The 19th International Symposium on Laser Precision Microfabrication.
Rung, S., Bokan, K., Rutsch, K., Schwarz, S., Esen, C., & Hellmann, R. (2018). Laser induced periodic surface structures on 100Cr6 steel for modification of friction demonstrated with stribeck test. In LPM2018 The 19th International Symposium on Laser Precision Microfabrication.
Girschikofsky, M., Rosenberger, M., Förthner, M., Rommel, M., Frey, L., & Hellmann, R. (2018, May). Flexible thin film bending sensor based on Bragg gratings in hybrid polymers. In Optical Sensing and Detection V (Vol. 10680, pp. 140-145). SPIE, doi: 10.1117/12.2303820.
Hessler, S., Schmauss, B., & Hellmann, R. (2018, May). Temperature corrected lab-on-a-chip platform with integrated epoxy polymer Bragg gratings. In Optical Sensing and Detection V (Vol. 10680, pp. 146-154). SPIE, doi: 10.1117/12.2306250.
Rosenberger, M., Hessler, S., Girschikofsky, M., Kefer, S., Belle, S., Hellmann, R., & Schmauss, B. (2018, April). High temperature stable polymer planar waveguide Bragg grating sensors. In 2018 IEEE 7th International Conference on Photonics (ICP) (pp. 1-3). IEEE, doi: 10.1109/ICP.2018.8533163.
Trautmann, A., Rüth, M., Lemke, H. D., Walther, T., & Hellmann, R. (2018, January). Large 3D direct laser written scaffolds for tissue engineering applications. In Nanophotonics Australasia 2017 (Vol. 10456, pp. 250-255). SPIE, doi: 10.1117/12.2282417.
Schwarz, S., Rung, S., & Hellmann, R. (2017). High quality one-dimensional low spatial frequency LIPSS on sapphire generated by Top-Hat beam shaped ultrashort-pulsed laser. In The Publications of the MultiScience-XXXI. MicroCAD International Scientific Conference., doi: 10.26649/musci.2017.019.
Koss, S., Edelmann, A., & Hellmann, R. (2017). Efficient Selective Laser Melting of AlSi10Mg0.5. In The Publications of the MultiScience-XXXI. MicroCAD International Scientific Conference., doi: 10.26649/musci.2017.020.
Schiller, B., Edelmann, A., & Hellmann, R. (2017). Characterization of Surface Quality for Inconel 625 Components Manufactured by Selective Laser Melting. In The Publications of the MultiScience-XXXI. MicroCAD International Scientific Conference., doi: 10.26649/musci.2017.022.
Riedel, L., Koss, S., Edelmann, A., & Hellmann, R. (2017). Design Rules to Prevent Thermal Distortion of Large Area Components Manufactured by Selective Laser Melting. In The Publications of the MultiScience-XXXI. MicroCAD International Scientific Conference., doi: 10.26649/musci.2017.021.
Belle, S., Hellmann, R., Helfert, S., & Jahns, J. (2017). Herstellung eines subwellenlängen-strukturierten Polarisationskonverters mittels Zwei-Photonen-Polymerisation und seine Charakterisierung. In Proceeding of DGaO Conferences 2017pp B10, ISSN: 1614-8436.
Koss, S., Edelmann, A., & Hellmann, R. (2017). Selective laser melting of AlSi10Mg0.5 using laser powers up to 1 kW. In Symposium on Additive Manufacturing (ISAM 2017).
Girschikofsky, M., Förthner, M., Rommel, M., Frey, L., & Hellmann, R. (2017, February). Fabrication of Bragg grating sensors in UV-NIL structured Ormocer waveguides. In Integrated Optics: Devices, Materials, and Technologies XXI (Vol. 10106, pp. 124-132). SPIE, doi: 10.1117/12.2249665.
Rosenberger, M., Hessler, S., Pauer, H., Girschikofsky, M., Roth, G. L., Adelmann, B., Woern, H., Schmauss, B., & Hellmann, R. (2017, February). Polymer planar waveguide Bragg gratings: fabrication, characterization, and sensing applications. In Integrated Optics: Devices, Materials, and Technologies XXI (Vol. 10106, pp. 322-330). SPIE, doi: 10.1117/12.2249830.
Hellmann, R. (2016). Ressourceneffizienz und Bauteilqualität additive gefertigter Kunststoffkomponenten. In Trends der Kunststoffverarbeitung Nr. 4.
Hessler, S., Schmauss, B., & Hellmann, R. (2016). Multiple optical Bragg grating sensors in planar epoxy waveguide structures. In Micro Photonics, doi: 10.13140/RG.2.2.18895.69280.
Rosenberger, M., Schmauss, B., & Hellmann, R. (2016, July). Temperature Referenced Polymer Planar Bragg Grating for Strain Sensing. In Optical Sensors (pp. SeW3D-4). Optica Publishing Group, doi: 10.1364/SENSORS.2016.SeW3D.4.
Pauer, H., Rosenberger, M., Girschikofsky, M., Hellmann, R., Tuschmann, W., & Woern, H. (2016, July). Towards 1-component Bragg-grating based shape sensing. In 2016 19th International Conference on Information Fusion (FUSION) (pp. 1909-1915). IEEE, ISBN: 978-0-9964-5274-8.
Schwarz, S., Rung, S., & Hellmann, R. (2016). Simulation of process parameters towards the generation of low spatial frequency LIPSS on dielectric materials. In MultiScience-XXX. microCAD International Multidisciplinary Scientific Conference., doi: 10.26649/musci.2016.016.
Krysciak, D., Rung, S., & Hellmann, R. (2016). Time dependance of wetting behaviour after applying low spatial frequency LIPSS with three different wavelengths on brass. In MultiScience-XXX. microCAD International Multidisciplinary Scientific Conference., doi: 10.26649/musci.2016.017.
Hessler, S., Schmauss, B., & Hellmann, R. (2015). Epoxy Resin Based Optofluidic Chip with Integrated Bragg Gratings. In POF Conference.
Girschikofsky, M., Förthner, M., Rommel, M., Frey, L., & Hellmann, R. (2015). Bragg Gratings in Imprinted Ormocer Waveguides. In POF Conference.
Rosenberger, M., Schmauss, B., & Hellmann, R. (2015). Potential of polymer planar waveguide Bragg gratings. In POF Conference.
Adelmann, B., Neumeier, B., Schleier, M., Wilmann, E., & Hellmann, R. (2015). Optical cutting tear detection system for industrial fiber laser based cutting machines. In Lasers in Manufacturing Procedings.
Rung, S., Preusch, F., & Hellmann, R. (2015). Generation of low-spatial frequency laser induced periodic surface structures driven by surface finish. In Lasers in Manufacturing Procedings.
Girschikofsky, M., Belle, S., Förthner, M., Fader, R., Rommel, M., Frey, L., & Hellmann, R. (2015). Optical Bragg gratings in inorganic-organic hybrid polymers for highly sensitive temperature measurements. In Proceedings of SENSOR 2015, 812-814, doi: 10.5162/sensor2015/P5.5.
Rosenberger, M., Eisenbeil, W., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2015). Polymer planar Bragg grating sensor for 2D strain sensing. In Proceedings of SENSOR 2015, doi: 10.5162/sensor2015/P5.1.
Förthner, M., Rumler, M., Michel, F., Rommel, M., Frey, L., Girschikofsky, M., Belle, S., Hellmann, R., & Klein, J. J. (2015). Comparison of surface relief Bragg gratings fabricated by UV-SCIL and volume index Bragg gratings based on hybrid polymers. In International Conference on Nanoimprint and Nanoprint Technology (NNT).
Adelmann, B., Hürner, A., Roth, G.-L., & Hellmann, R. (2015). Substrate thinning of SiC semiconductor components using fiber laser. In Proceedings of the 7th International Congress on Laser Advanced Materials Processing (No. 15).
Adelmann, B., & Hellmann, R. (2015). Comparative study of experimentally determined and simulated mechanical strength of fiber laser cut alumina substrates. In Proceedings of the 7th International Congress on Laser Advanced Materials Processing (No. 15).
Preusch, F., Rung, S., & Hellmann, R. (2015). Influence of surface finish for the generation of LIPSS. In Proceedings of the 7th International Congress on Laser Advanced Materials Processing (No. 15).
Belle, S., Edelmann, A., Hellmann, R., & Jahns, J. (2015). Fabrication of subwavelength-structured hollow waveguide array by two-photon polymerization. In 116th annual meeting of the DGaO, ISSN: 1614-8436.
Trautmann, A., Hellmann, R., & Walther, T. (2015). Fabrication and characterization of 3D direct laser written structures using 515 nm and 780 nm. In Vortrag auf der DPG-Frühjahrstagung.
Jäger, E., Bischoff, C., Rädel, U., Runge, A., Rung, S., & Hellmann, R. (2015). Parallel-Prozessierung und Top-Hat-Strahlformung zur Effizienzsteigerung in der Lasermaterialbearbeitung. In 18. Laser in der Elektronikproduktion und Feinwerktechnik (LEF2015).
Rung, S., Bischoff, C., Jäger, E., & Hellmann, R. (2015). Possibilities to enhance laser thin film ablation by using diffractive optical elements. In Industrial Laser Solutions Magazine 1.
Rosenberger, M., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2015, January). TOPAS-based humidity insensitive polymer planar Bragg gratings for temperature and multi-axial strain sensing. In International Seminar on Photonics, Optics, and Its Applications (ISPhOA 2014) (Vol. 9444, pp. 43-48). SPIE, doi: 10.1117/12.2075009.
Hessler, S., Rosenberger, M., Belle, S., Schmauss, B., & Hellmann, R. (2014). Controlling the Spectral Filter Characteristics of Polymer Planar Bragg Gratings by the Photomechanical Effect Of Multi-Walled Carbon Nanotubes. In 40th International conference on Micro and Nano Engineering (MNE2014).
Belle, S., Rosenberger, M., Jahns, J., & Hellmann, R. (2014). Fabrication of an optical micro reflector array by two-photon polymerization technique with ultrafast galvo scanner technology. In 40th International conference on Micro and Nano Engineering (MNE2014).
Rosenberger, M., Hessler, S., Belle, S., Schmauss, B., & Hellmann, R. (2014, July). Multi-axial strain sensing using polymer planar Bragg gratings. In Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides (pp. BM3D-2). Optica Publishing Group, doi: 10.1364/BGPP.2014.BM3D.2.
Förthner, M., Fader, R., Rumler, M., Rommel, M., Frey, L., Girschikofsky, M., Belle, S., Hellmann, R., & Klein, J. J. (2014). Large area fabrication of hybrid polymer waveguides for planar Bragg grating sensors using UV-enhanced Substrate Conformal Lithography (UV-SCIL). In 13th International Conference on Nanoimprint and Nanoprint Technology (NNT2014).
Jäger, E., Rädel, U., Bischoff, C., Umhofer, U., Rung, S., & Hellmann, R. (2014). Laser micromachining–parallel processing with multiple top hat beams. In 8th International Conference on Photonic Technologies LANE 2014.
Rung, S., Bischoff, C., Jäger, E., Umhofer, U., & Hellmann, R. (2014, March). Laser thin film ablation with multiple beams and tailored beam profiles. In Laser Applications in Microelectronic and Optoelectronic Manufacturing (LAMOM) XIX (Vol. 8967, pp. 137-149). SPIE.
Rosenberger, M., Hartlaub, N., Koller, G., Belle, S., Schmauss, B., & Hellmann, R. (2013, May). Polymer planar Bragg grating for sensing applications. In Optical Sensors 2013 (Vol. 8774, pp. 389-395). SPIE., doi: .
Brehm, M., Girschikofsky, M., & Hellmann, R. (2013). Optical Planar Bragg Grating Sensor for pH-Measurements. In Proceedings of the XXVII MicroCAD International Scientific Conference – Applied Materials Science and Technologies.
Hessler, S., Rosenberger, M., Belle, S., & Hellmann, R. (2013). Characterization of UV-written optical waveguides in PMMA by phase-shifting Mach-Zehnder Interferometry. In Proceedings of the XXVII MicroCAD International Scientific Conference – Applied Materials Science and Technologies.
Girschikofsky, M., Rosenberger, M., Belle, S., & Hellmann, R. (2013). Surface modifications of planar bragg grating refractive index sensors for gas detection. In Proceedings of the XXVII MicroCAD International Scientific Conference – Applied Materials Science and Technologies.
Koller, G., Hessler, S., Rosenberger, M., Belle, S., & Hellmann, R. (2013). Optical Waveguide Fabrication in PMMA Using Low Frequency Reactive Ion Etching. In Proceedings of the XXVII MicroCAD International Scientific Conference – Applied Materials Science and Technologies.
Hasenstab, S., Adelmann, B., & Hellmann, R. (2013). Laser Cutting of Alumina and Aluminum Nitride with a 500 W Single Mode Fiber Laser. In Proceedings of the XXVII MicroCAD International Scientific Conference – Applied Materials Science and Technologies.
Rung, S., Rexhepi, M., & Hellmann, R., Beam shaping for enhanced throughput of laser ablation of transparent conductive films. In Proceedings of the XXVII MicroCAD International Scientific Conference – Applied Materials Science and Technologies.
Hürner, A., Schlegl, T., Adelmann, B., Mitlehner, H., Hellmann, R., Bauer, A. J., & Frey, L. (2013, March). Alloying of ohmic contacts to n-type 4H-SiC via laser irradiation. In Materials Science Forum (Vol. 740, pp. 773-776). Trans Tech Publications Ltd., doi: 10.4028/www.scientific.net/MSF.740-742.773.
Kalmár, L., Hellmann, R., Tamás, R., & Vigh, V. (2013). Investigation of heat transport procedure in UV LED module. In Special Issue of the Hungarian Technical Periodical GÊP 2, pp. 31-34.
Girschikofsky, M., Rosenberger, M., Belle, S., Brutschy, M., Waldvogel, S. R., & Hellmann, R. (2012, May). Functionalized planar Bragg grating sensor for the detection of BTX in solvent vapor. In Optical Sensing and Detection II (Vol. 8439, pp. 346-351). SPIE, doi: 10.1117/12.921078.
Girschikofsky, M., Rosenberger, M., Belle, S., Brutschy, M., Waldvogel, S. R., & Hellmann, R. (2012). ɑ-Cyclodextrin functionalized planar Bragg grating sensor for the detection of small arene traces in solvent vapourIn Proceedings IMCS 2012, 646-648, doi: 10.5162/IMCS2012/7.5.1.
Bischoff, C., Jäger, E., Rung, S., & Hellmann, R. (2012). Diffractive beam shaping optics for efficient micromachining. In Proceedings of the LASYS (Internationale Fachmesse für Laser-Materialbearbeitung)–SLT (Stuttgarter Lasertage) 2012.
Hürner, A., Schlegl, T., Adelmann, B., Mitlehner, H., Hellmann, R., Bauer, A. J., & Frey, L. (2013, March). Alloying of ohmic contacts to n-type 4H-SiC via laser irradiation. In Materials Science Forum (Vol. 740, pp. 773-776). Trans Tech Publications Ltd., doi: 10.4028/www.scientific.net/MSF.740-742.773.
Rung, S., & Hellmann, R. (2012). Laser scribing of metallized transparent conductive oxide–A comparative study using top hat and Gaussian beam profiles. In Proceedings of the XXVI International MicroCAD Conference.
Kalmár, L., Hellmann, R., Régert, T., & Varga, Z. (2012). Numerical investigation of heat transport procedure in high power LED modules. In Proceedings of the XXVI International MicroCAD Conference, (pp. 43-46).
Varga, Z., Kalmár, L., & Hellmann, R. (2012). Numerical analysis of heat transport procedure in a UV LED module. In Special Issue of the Hungarian Technical Periodical GÊP, pp. 41-44.
Schneider, J., Bochtler, U., Hellmann, R., Kaloudis, M., & Gockel, T. (2012). Optimierung des Kühl-konzeptes zur Aktivkühlung eines Hochleistungs-UV-LED-Moduls. In Elektor Sonderheft LED VI, pp. 20-28.
Hellmann, R., & Gockel, T. (2012). Optische Charakterisierung von Leuchtdioden. In Elektor Sonderheft LED IV, pp. 40-46.
Rosenberger, M., Belle, S., & Hellmann, R. (2011, May). Detection of biochemical reaction and DNA hybridization using a planar Bragg grating sensor. In Optical Sensors 2011; and Photonic Crystal Fibers V (Vol. 8073, pp. 75-81). SPIE. doi: 10.1117/12.886785.
Rosenberger, M., Belle, S., & Hellmann, R. (2011). Detection of unlabeled DNA hybridization with a planar bragg grating sensor. In Proceeding XXV microCAD, International scientific conference.
Rosenberger, M., Belle, S., & Hellmann, R. (2011). Optical interrogation of chemical and temperature bragg grating sensors using tunable fiber coupled bandpass filter. In Proceeding XXV microCAD, International scientific conference.
Belle, S., Rosenberger, M., & Hellmann, R. (2011). Optical fibre sensing in the production process and storage of biofuels. In Proceeding XXV microCAD, International scientific conference.
Heilmann, E.-M., & Hellmann, R. (2011). High Speed Fiber Material processing of Stainless Steel Tapes Under Tension. In Proceeding XXV microCAD, International scientific conference.
Heilmann, E.-M., & Hellmann, R. (2011). Water Jet Guided Laser Cutting Using A Green Disc Laser. In Proceeding XXV microCAD, International scientific conference.
Adelmann, B., & Hellmann, R. (2011). Different modulation schemes in fibre laser cutting. In Proceeding XXV microCAD, International scientific conference.
Adelmann, B., & Hellmann, R. (2011). DOE based optimization of fibre laser cutting of metals. In Proceeding XXV microCAD, International scientific conference..
Risch, A., & Hellmann, R. (2011). Laser Induced Modification of GZO Thin Film. In Proceeding XXV microCAD, International scientific conference.
Risch, A., & Hellmann, R. (2011). ITO thin film laser patterning by picosecond laser. In Proceeding XXV microCAD, International scientific conference.
Hellmann, R., & Moorhouse, C. (2011). Laser patterning of transparent electrode films, from solar panels through high-end display. In Industrial Laser Solutions Magazine, (11).
Schneider, J., Bochtler, U., Hellmann, R., Kaloudis, M., & Gockel, T. (2011). Effiziente Entwärmung eines Hochleistungs-UV-LED-Moduls. In Elektor, Sonderheft LEDs 3(9), 12-17.
Risch, A., Christiansen, A., Hellmann, R., & Gockel, T. (2011). Laserstrukturierung vonTCOs zur Herstellung organischer Leuchtdioden. In Elektor, Sonderheft LEDs 3(9), 39-41.
Kalmár, L., Hellmann, R., Régert, T., & Varga, Z. (2011). Numerical simulation of heat transfer procedure in high power LED modules. In Proceedings of the 12th technical and scientific meeting (pp. 18-20).
Amrhein, F., Kehrer, M., Schreck, T., Bochtler, U., Hellmann, R., & Kaloudis, M. (2011). Schnelle Aushärtung auch im Schatten: UV-LED-Bestrahlung von Vergussmaterial. In adhäsion KLEBEN & DICHTEN, 55, 38-41.
Gockel, T., Engel, M., & Hellmann, R. (2011). 3D Laserscanning mit Linienlaser und Smart Camera–Systemauslegung mit Rasterlinsenoptik und Scheimpflugentzerrung. In Elektor Sonderheft LEDs 3,(9), 79-84.
Belle, S., Scheurich, S., Hellmann, R., So, S., Sparrow, I. J. G., & Emmerson, G. D. (2010, May). Refractive index sensing for online monitoring water and ethanol content in bio fuels. In Optical sensing and detection (Vol. 7726, pp. 448-453). SPIE, doi: 10.1117/12.853849.
Hühnlein, K., Tschirpke, K., & Hellmann, R. (2010). Optimization of laser cutting processes using design of experiments. In 6th International Conference on Laser Assisted Net Shape Engineering, doi: 10.1016/j.phpro.2010.08.050.
Mozin, M., & Hellmann, R. (2010). Gas supported laser remote fusion cutting, in Production Engineering and Manufacturing Systems. In Proceedings of the XXIV microCAD, International scientific conference.
Risch, A., Hühnlein, K., Knöll, J., & Hellmann, R. (2010). Picosecond and nanosecond pulsed laserscribing on transparent conductive indium tin oxide. In Proceedings of the XXIV microCAD, International scientific conference.
Glaab, J., & Hellmann, R. (2010). Small-scale low-through UV-C LED disinfection device, in waste processing and recycling. In Proceedings of the XXIV microCAD, International scientific conference.
Kaloumenos, M., Amrhein, F., Glaab, J., Sauer, M., Hellmann, R., & Kaloudis, M. (2010). Development of a UV-Light Source with Highest Power Density Based on Light Emitting Diode Technology for Applications in Production Engineering, in Production Engineering and manufacturing Systems. In Proceedings of the XXIV microCAD, International scientific conference.
Bochtler, U., Hellmann, R., & Kaloudis, M. (2010). Neuartige UV-Lichtquelle auf Leuchtdiodenbasis, Packaging und Hybridschaltungen. In PLUS, (2).
Glaab, J., & Hellmann, R. (2010). Germicidal potential of ultraviolet-LED emitting different wavelength for the inactivation of indigenous coliform bacteria. In Water research conference.
Hellmann, R., Glaab, J., & Gockel, T. (2010). Wasserentkeimung mit UV-Leuchtdioden. In Elektor Sonderheft, LEDs 2(2), 40-45.
Bochtler, U., Hellmann, R., Kaloudis, M., Amrhein, F., Glaab, J., Kaloumenos, M., Sauer, M., & Gockel, T. (2010). LUVLED-UV-Leistungslichtquelle auf Leuchtdiodenbasis. In Elektor Sonderheft, LEDs 2(2), 57-63.
Amrhein, F., Bochtler, U., Hellmann, R., Kaloudis, M., & Kaloumenos, M. (2010). Vergleich der thermischen Eigenschaften unterschiedlicher insulated metal substrat-Leiterplatten. In PLUS, Leiterplattentechnik,(8), 1758.
Rosenberger, M., Belle, S., & Hellmann, R. (2009). Optical interrogation of bragg grating sensors using tunable fibre based bandpass filter. In Proceedings of the 20st international science conference, Mittweida.
Belle, S., Scheurich, S., Hellmann, R., Sparrow, I. J. G., & Emmerson, G. D. (2009, May). Interrogating water content in organic solvents by planar Bragg grating sensor. In Proceedings of the Sensors & Test Conference (Vol. 2, pp. 324-329), doi: 10.5162/sensor09/v2/p3.2.
Scheurich, S., Belle, S., Hellmann, R., So, S., Sparrow, I. J. G., & Emmerson, G. (2009, May). Application of a silica-on-silicon planar optical waveguide Bragg grating sensor for organic liquid compound detection. In Optical Sensors 2009 (Vol. 7356, pp. 335-342). SPIE, doi: 10.1117/12.820484.
Scheurich, S., Belle, S., Hellmann, R., So, S., Sparrow, I., & Emmerson, G. (2009). Planar optical waveguide bragg grating chemical sensor for online process control. In 3rd integrated optics-sensors, sensing structures and methodes.
Risch, A., Hühnlein, K., Knöll, J., & Hellmann, R. (2009). Laserscribing of transparent conductive oxides-a comparative study using nanosecond and picosecond pulsed solid state lasers. In Proceedings of the 20st International Scientific Conference.
Euteneuer, A., Shevel, S., Hellmann, R., Göbel, E. O., Vozny, V., Vytrykhivsky, M., Petri, W., & Klingshirn, C. (1997). The Effect of Disorder on Exciton Dynamics in Cation-Substituted ZnCdS Mixed crystal. In International Conference on II-VI Compounds and Devices.
Göbel, E. O., Hellmann, R., Mackh, G., Yakovlev, D. R., Ossau, W., Waag, A., & Landwehr, G. (1995, February). Picosecond Dynamics of Magnetic Polarons in Semimagnetic Quantum Well Structures. In Materials Science Forum (Vol. 182, pp. 519-524). Trans Tech Publications Ltd., doi: 10.4028/www.scientific.net/MSF.182-184.519.
Hellmann, R., Cundiff, S. T., Kuhn-Heinrich, B., Koch, M., Yakovlev, D. R., Feldmann, J., ... & Landwehr, G. (1995, February). Dephasing of Localized and Delocalized Excitons in Disordered CdTe/(Cd, Mg) Te Multiple Quantum Wells. In Materials Science Forum (Vol. 182, pp. 199-202). Trans Tech Publications Ltd., doi: 10.4028/www.scientific.net/MSF.182-184.199.
Verbin, S. Y., Hellmann, R., Baranovskii, S. D., Ruckes, K., Grigorev, S. R., Novikov, B. V., ... & Thomas, P. (1995, February). New luminescence band in II-VI semiconductor crystals with treated surfaces. In Materials Science Forum (Vol. 182, pp. 279-282). Trans Tech Publications Ltd., doi: 10.4028/www.scientific.net/MSF.182-184.279.
Cundiff, S. T., Hellmann, R. H., Koch, M., Yakovlev, D. R., Waag, A., Göbel, E. O., & Landwehr, G. (1995, February). Subpicosecond Optical Dephasing in Diluted Magnetic Semiconductors. In Materials Science Forum (Vol. 182, pp. 735-738). Trans Tech Publications Ltd., doi: 10.4028/www.scientific.net/MSF.182-184.735.
Mackh, G., Ossau, W., Yakovlev, D. R., Hellmann, R., Gobel, E. O., Wojtowicz, T., Karczewski, G., Kossut, J., & Landwehr, G. (1995). Exciton Magnetic Polarons in Strongly Confined CdTe/(CdMn) Te Quantum Wells. In Proc. Int. Conf. Semicond. Heterostr., Montpellier
Mackh, G., Ossau, W., Yakovlev, D. R., Hellmann, R., Göbel, E. O., Waag, A., & Landwehr, G. (1995, February). Exciton Magnetic Polarons in Semimagnetic Quantum Wells with Nonmagnetic Barriers. In Materials Science Forum (Vol. 182, pp. 775-778). Trans Tech Publications Ltd, doi: 10.4028/www.scientific.net/MSF.182-184.775.
Hellmann, R., Cundiff, S. T., Koch, M., Feldmann, J., Göbel, E. O., Mackh, G., Waag, A., & Landwehr, G. (1995). Dephasing of Localized and Delocalized Excitons in Disordered CdMnTe/CdMgTe Quantum Wells. In Quantum Electronics and Laser Science Conference, ISBN: 1-55752-402-5.
Hellmann, R., Euteneur, A., Hense, S. G., Feldmann, J., Thomas, P., Göbel, E. O., Waag, A., & Landwehr, G. (1996). Low Temperature Anti-Stokes Luminescence in CdTe/(Cd, Mg) Te Quantum Well Structures. In Hot Carriers in Semiconductors, 53-55, doi: 10.1007/978-1-4613-0401-2_12.
Mackh, G., Yakovlev, D. R., Ossau, W., Hellmann, R., Euteneuer, A., Göbel, E. O., Waag, A, Fischer, F., & Landwehr, G., (1995). Effect of Dynamics and Dimensionality on the Stability of Exciton Magnetic Polarons in CdTe/CdMnMgTe Heterostructures In International Conference on Semiconductor Heteroepitaxie.
Yakovlev, D. R., Mackh, G., Ossau, W., Waag, A., Landwehr, G., Hellmann, R., & Göbel, E. O. (1994). Exciton magnetic polarons in short-period CdTe/CdMnTe superlattices. In International Conference on Physics of Semiconductors.
Hellman, R., Pohlmann, A., Göbel, E. O., Yakovlev, D. R., Waag, A., Bicknell-Tassius, R. N., Landwehr, G. (1992). Time-Resolved Photoluminescence Studies of Exciton Recombination and Perpendicular Transport in CdTe/CdMnTe Quantum Wells and Superlattices. In International Conference on Physics of Semiconductor.