@book{13336, abstract = {{Das Lehr- und Arbeitsbuch entspricht der Einführungsvorlesung der Elektrotechnik an Hochschulen und ist explizit für das Selbststudium konzipiert. Von den physikalischen Grundlagen, elektrotechnischen Grundbegriffen und elektromagnetischen Feldern bis hin zu Fourier-Reihen und transienten Vorgängen werden in 22 Kapiteln grundlegende und vertiefende Vorlesungsinhalte der Elektrotechnik wiedergegeben. Aufgaben, Lösungen und kleinere Zusammenfassungen am Ende jedes Kapitels unterstützen beim selbstständigen Lernen und Erarbeiten der Inhalte. Das Buch führt als Selbststudium leicht lesbar durch die Basis der Elektrotechnik. Das Lernen mit diesem Arbeitsbuch ist in einem Bachelor-Fernstudiengang Elektrotechnik erprobt.}}, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-658-49183-3}}, keywords = {{Automotive Engineering, Computer Engineering and Networks, Electrical and Electronic Engineering, Marine Engineering, Mechanical Engineering, Civil Engineering}}, pages = {{587}}, publisher = {{Springer Vieweg}}, title = {{{Elektrotechnik zum Selbststudium : Grundlagen und Vertiefung}}}, year = {{2026}}, } @misc{13338, abstract = {{This work discusses the additive manufacturing of an axicon lens using cyclic olefin copolymer (TOPAS), and its characterization between 100 GHz and 300 GHz. The proposed manufacturing process followed by dip-coating post-processing provides an improved surface finish. Additionally, the terahertz output of the lens remains intact over the entire frequency range.}}, author = {{Shrotri, Abhijeet Narendra and Joshi, Suraj and Vogel, Lea and Starsaja, Annamarija and Stübbe, Oliver and Preu, Sascha}}, booktitle = {{2025 50th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)}}, keywords = {{Manufacturing processes, Surface waves, Three-dimensional printing, Surface finishing, Surface treatment, Lenses}}, location = {{ Helsinki, Finland }}, pages = {{2}}, publisher = {{IEEE}}, title = {{{Terahertz Axicon Lenses}}}, doi = {{10.1109/irmmw-thz61557.2025.11319870}}, year = {{2026}}, } @misc{13339, abstract = {{Additive manufacturing (AM) paves the way for low-cost production of optical and terahertz (THz) components such as waveguides, fibers, and lenses [1]–[3]. This work addresses the fabrication and THz characterization of a 3D-printed waveguide composed of cyclic olefin copolymer (TOPAS). Such a waveguide is a convenient and inexpensive tool in the development of THz interconnects, and in applications such as biomedical sensing.}}, author = {{Joshi, Suraj and Starsaja, Annamarija and Shrotri, Abhijeet Narendra and Stübbe, Oliver and Preu, Sascha}}, booktitle = {{2025 50th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)}}, keywords = {{Optical fibers, Optical fiber sensors, Optical interconnections, Biomedical optical imaging, Optical device fabrication, Production, Optical waveguide components, Three-dimensional printing, Optical waveguides, Lenses}}, location = {{Helsinki, Finland }}, publisher = {{IEEE}}, title = {{{Additively-Manufactured Terahertz Waveguides}}}, doi = {{10.1109/irmmw-thz61557.2025.11320095}}, year = {{2026}}, } @unpublished{13346, abstract = {{This article discusses the additive manufacturing and post-processing of axicons, and their performance evaluation using attenuation and near-field-measurements based fundamental techniques. The axicons are manufactured using the materials cyclic olefin copolymer (TOPAS) and polymethyl methacrylate (PMMA), for their respective use in terahertz and near-infrared applications. An emphasis is placed on the dip-coating-based post-processing. Interval dipping and intermittent hardening lead to excellent surface finish and transparency in case of additively-manufactured near-infrared axicons. The dip-coated samples exhibit surface roughness of sub 10nm, and a uniformly distributed thin layer coating over the axicon surface. In addition to the improved surface finish and transparency, the coatings are also closely matched in refractive index to the axicon material. Such post-processed axicons pave the way for rapid-prototyping and production.}}, author = {{Shrotri, Abhijeet Narendra and Starsaja, Annamarija and Joshi, Suraj and Preu, Sascha and Stübbe, Oliver}}, booktitle = {{Optica Open}}, issn = {{2334-2536 }}, keywords = {{additive manufacturing, stereolithography, dip-coating, post-processing}}, pages = {{5}}, publisher = {{Optica Publishing Group}}, title = {{{Multispectral characterization of additively manufactured and dip-coated axicons}}}, doi = {{https://doi.org/10.1364/opticaopen.31149016}}, year = {{2026}}, } @unpublished{13363, abstract = {{This article discusses the additive manufacturing and post-processing of axicons, and their performance evaluation using attenuation and near-field-measurements based fundamental techniques. The axicons are manufactured using the materials cyclic olefin copolymer (TOPAS) and polymethyl methacrylate (PMMA), for their respective use in terahertz and near-infrared applications. An emphasis is placed on the dip-coating-based post-processing. Interval dipping and intermittent hardening lead to excellent surface finish and transparency in case of additively-manufactured near-infrared axicons. The dip-coated samples exhibit surface roughness of sub 10 nm, and a uniformly distributed thin layer coating over the axicon surface. In addition to the improved surface finish and transparency, the coatings are also closely matched in refractive index to the axicon material. Such post-processed axicons pave the way for rapid-prototyping and production.}}, author = {{Shrotri, Abhijeet Narendra and Starsaja, Annamarija and Joshi, Suraj and Preu, Sascha and Stübbe, Oliver}}, booktitle = {{Photonics: Open Access Journal}}, issn = {{2304-6732 }}, keywords = {{additive manufacturing, stereolithography, dip-coating, post-processing}}, pages = {{15}}, publisher = {{MDPI }}, title = {{{Multispectral Characterization of Additively Manufactured and Dip-Coated Axicons}}}, doi = {{https://doi.org/10.20944/preprints202602.0389.v1}}, year = {{2026}}, } @misc{13495, abstract = {{The use of additive manufacturing for rapid prototyping of near-infrared and terahertz components provides seamless and error-free production. This article discusses the additive manufacturing and post-processing of axicons and their performance evaluation using attenuation and near-field-measurements based fundamental techniques. The axicons are manufactured using the materials cyclic olefin copolymer (TOPAS) and polymethyl methacrylate (PMMA), for their respective use in terahertz and near-infrared applications. The optical and terahertz components manufactured using traditional 3D-printing processes, e.g., fused filament fabrication or stereolithography apparatus exhibit high surface roughness in the range of 15 ± 2.5 µm, resulting in undesired propagation and scattering in the near infrared wavelengths. This research work proposes an economical post-processing technique for additively manufactured terahertz and near-infrared axicons for applications in multispectral characterization, e.g., bio-sensing. The authors used an enhanced method of dip-coating, which involves interval dipping and intermittent hardening to achieve better surface finish. An emphasis is placed on interval dipping and intermittent hardening, which lead to excellent transparency in case of additively-manufactured near-infrared axicons. The dip-coated samples exhibit surface roughness below 10 nm. With the use of heated resin material as the coating layer, due to reduced viscosity, the resin material distributes uniformly over the surface of the 3D-printed terahertz and near-infrared axicons. The authors also observed that the DOF length deviation between unprocessed and enhanced dip-coated axicons remains within the measurement error estimation from analytical calculations. In addition to the improved surface finish and transparency, the coatings are also closely matched in refractive index to the axicon material. Such post-processed axicons pave the way for producing a wide array of systems in the fields of communication, imaging, and bio-sensing.}}, author = {{Shrotri, Abhijeet Narendra and Starsaja, Annamarija and Joshi, Suraj and Preu, Sascha and Stübbe, Oliver}}, booktitle = {{Photonics}}, issn = {{2304-6732}}, keywords = {{additive manufacturing, stereolithography, dip-coating, post-processing}}, number = {{3}}, publisher = {{MDPI AG}}, title = {{{Multispectral Characterization of Additively Manufactured and Dip-Coated Axicons}}}, doi = {{10.3390/photonics13030264}}, volume = {{13}}, year = {{2026}}, } @misc{13481, abstract = {{Additive manufacturing (AM), commonly known as 3D-printing, provides a cost-effective approach for manufacturing of prototypes. The authors illustrate material analysis of suitable 3D-printable materials that can be used to manufacture THz components and investigate and provide solutions to challenges occurring during the 3D printing process. Samples in this study are 3D-printed using fused filament fabrication (FFF) based 3D-printers Ultimaker S5 and Bambu Lab X1E. We investigate a total of six materials: High Impact Polystyrene (HIPS), High Density Polyethylene (HDPE), Cyclic Olefin Copolymer (TOPAS), Polypropylene (PP), Polycarbonate (PC) and Polytetrafluoroethylene (PTFE/ Teflon). We observed that the Teflon material contains PC as material dopant to reduce the melting temperature. The authors observed warping of the 3D-structure due to the poor adhesion of material on the print-bed. An adhesive fluid or adhesive sheet applied on the print-bed before 3D-printing provides proper adhesion. Air gaps formed between the adjacent layers during the 3D-printing results into incorrect evaluations. The 3D-printing setting of material flow ratio above 100% ensures the filling of air gaps created due to layer-by-layer manufacturing. Moreover, the direction of nozzle movement also helps in achieving uniformity in 3D-printed sample. A minimal layer height of 100 µm for the 3D-printing of all the materials provides promising adhesion and better finish. Some materials e.g., PP, PC, TOPAS capture humidity, therefore the authors used specialized chambers to maintain low humidity during the whole 3D-printing process. Fan speed, low surrounding temperature contribute in blocking of the nozzles or premature cooling of the samples; therefore, it is necessary to maintain the temperature during 3D-printing. We investigated these samples using THz-TDS setup to find the most suitable material for AM of THz-components. The results reveal that the absorption coefficient of TOPAS is the least (α < 0.5 per cm at 0.4 THz) among all the investigated materials. Therefore, with the help of material analysis of 3D-printable materials for manufacturing of THz-components, the authors introduce fundamental research results for the future developments in the field of 3D-printing of THz components. [1] A. Shrotri, A. K. Mukherjee et. al.: Additive manufacturing and characterization of hollow core metal and topas waveguides for Terahertz sensor systems, 2023 IRMMW-THz, Montreal, QC, Canada, doi: 10.1109/IRMMW-THz57677.2023.10299134. [2] A. Shrotri, S. Joshi et. al.: THz-Characterization of Inkjet Printable Polymers,2025 French-German THz Conference, Siegen, Germany, 2025 [3] A. Shrotri, A. K. Mukherjee, et. al.: THz-Characterization of Additively Manufactured Spiral Shaped Waveguides, 2023 IEEE APCAP, Guangzhou, China, 2023, pp. 1-2, doi: 10.1109/APCAP59480.2023.10469842 [4] S. Joshi, A. Starsaja, et. al.: Additively Manufactured Terahertz Waveguides, 2025 50th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), Helsinki, Finland, 2025, pp. 1-2, doi: 10.1109/IRMMW-THz61557.2025.11320095 [5] A. Shrotri, S. Joshi, et. al.: Terahertz Axicon Lenses, 2025 50th IRMMW-THz, Helsinki, Finland, 2025, pp. 1-2, doi: 10.1109/IRMMW-THz61557.2025.11319870 }}, author = {{Shrotri, Abhijeet Narendra and Starsaja, Annamarija and Joshi, Suraj and Rushd Faridi, Fahd and Stübbe, Oliver and Preu, Sascha }}, booktitle = {{12th International Workshop on THz Technolgy and Applications}}, location = {{Kaiserslautern}}, title = {{{Overcoming Material and Process Challenges in 3D-printed Terahertz Components}}}, doi = {{10.13140/RG.2.2.28438.72002}}, year = {{2026}}, } @misc{12424, abstract = {{Additive manufacturing of optical, electrical, and mechanical components is a beneficial approach for the rapid prototyping of components and error elimination, with short turnaround times. However, additively manufactured components usually have rough surfaces that need post-processing, particularly for optical components, where the surface roughness must be a small fraction of the wavelength. We demonstrate an innovative and economical approach by dip-coating with the same resin used for printing in a simple post-processing step, providing high transparency to the 3D-printed optical components and reducing surface roughness while achieving perfect index matching of the coating layer. The surface roughness of the 3D-printed optical components drops to 5 nm (arithmetic average) after the dip-coating process. We observed significant performance enhancements after comparing the unprocessed optical components and the dip-coated optical components, including optical transparency and a shiny surface finish for previously rough surfaces.}}, author = {{Shrotri, Abhijeet Narendra and Preu, Sascha and Stübbe, Oliver}}, booktitle = {{Coatings : open access journal}}, issn = {{2079-6412}}, keywords = {{additive manufacturing, post-processing, optics, dip-coating}}, number = {{2}}, publisher = {{MDPI AG}}, title = {{{Achieving Transparency and Minimizing Losses of Rough Additively Manufactured Optical Components by a Dip-Coating Surface Finish}}}, doi = {{10.3390/coatings15020210}}, volume = {{15}}, year = {{2025}}, } @misc{13025, abstract = {{Additive manufacturing (AM) of terahertz (THz) components is a cost-effective and efficient method of rapid prototyping. This work discusses the THz characterization of AM-compatible polymers to evaluate their potential use in the fabrication of THz components. The materials under investigation are primarily used in the inkjet 3D-printing (IP) process, and are compared with other AM-compatible materials [1]. The authors analyzed heat resistant AR-H1 material, transparent AR-M2 material and flexible silicon elastomer material. After the THz time domain spectroscopy of these materials, it can be deduced that the materials AR-M2 and AR-H1 can be used in manufacturing of THz components, with the benefit of a superior printing resolution of 50 µm. [1] A. Shrotri, A. K. Mukherjee, S. Lohöfener, A. Springer, O. Stübbe and S. Preu, "Additive manufacturing and characterization of hollow core metal and topas waveguides for Terahertz sensor systems," 2023 48th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), Montreal, QC, Canada, 2023, pp. 1-2, doi: 10.1109/IRMMW-THz57677.2023.10299134.}}, author = {{Shrotri, Abhijeet Narendra and Joshi, Suraj and Rushd Faridi, Fahd and Stübbe, Oliver and Preu, Sascha}}, location = {{Siegen}}, title = {{{THz Characterization of Inkjet Printable Polymers}}}, year = {{2025}}, } @unpublished{13029, abstract = {{Additive manufacturing of optical, electrical and mechanical components is a beneficial approach for rapid prototyping of components and error elimination with short turn around times. However, additively manufactured components usually have rough surfaces which need post-processing, in particular for optical components where the surface roughness must be a small fraction of the wavelength. We demonstrate an innovative and economical approach by dip-coating with the same resin as used for printing, providing high transparency of the 3D-printed optical components and reduced surface roughness with perfect index matching of the coating layer in a simple post processing step. The surface roughness of the 3D-printed optical components drops to 5 nm (arithmetic average) after the dip-coating process. We observed significant performance enhancement after comparing the unprocessed optical components and dip-coated optical components, including achieving optical transparency and shiny surface finish of previously rough surfaces.}}, author = {{Shrotri, Abhijeet Narendra and Preu, Sascha and Stübbe, Oliver}}, booktitle = {{Coatings : open access journal}}, keywords = {{additive manufacturing, post-processing, optics, dip-coating}}, pages = {{10}}, publisher = {{MDPI}}, title = {{{Achieving Transparency and Minimizing Loss of Rough Additively Manufactured Optical Components by a Dip-Coating Surface Finish}}}, doi = {{10.20944/preprints202501.1899.v1}}, year = {{2025}}, } @misc{11229, abstract = {{Additive manufacturing enables direct prototyping of complex 3D-objects that are difficult to manufacture using conventional methods. It is widely used to fabricate cost-efficient prototypes and portrays as a bridging technology to connect different scientific and industrial fields, e.g. Engineering, Medicine, etc. Consequently, additive manufacturing finds its applications in the production of patient-specific orthoses. This paper discusses the application of the stereolithography apparatus process to develop a pressure sensor based on an optical waveguide principle to embed into a below-knee orthosis. For Orthopaedic patients, the below-knee orthosis must be adjusted to the lower leg at regular intervals due to anthropometric changes in patient’s body to achieve proper mobility and correct load. Currently, this alteration relies on the patient’s estimation of support load and is only sub-optimal. Hence, the concept of developing an intelligent orthosis with a novel embedded optical system to monitor the exact support load at the neuralgic is proposed. }}, author = {{Shahane, Akshay Manoj and Shrotri, Abhijeet Narendra and Wittenbröker, Christian and Stübbe, Oliver}}, booktitle = {{Laser 3D Manufacturing XI}}, editor = {{Gu, Bo and Chen, Hongqiang}}, location = {{San Francisco, California, United States}}, publisher = {{SPIE}}, title = {{{Additively manufactured pressure sensor for embedding in 3D-printed below-knee orthosis}}}, doi = {{10.1117/12.2692220}}, volume = {{12876}}, year = {{2024}}, } @misc{11286, abstract = {{This paper provides insight of additive manufacturing of spiral shaped waveguides using suitable low loss polymer materials and their THz characterization for the frequency range of 0.1 THz to 0.6 THz. The spiral shaped waveguides are evaluated for material losses as well as in-and outcoupling losses with respect to the increasing length of the waveguides.}}, author = {{Shrotri, Abhijeet Narendra and Mukherjee, Amlan k. and Stübbe, Oliver and Preu, Sascha}}, booktitle = {{2023 IEEE 11th Asia-Pacific Conference on Antennas and Propagation (APCAP)}}, isbn = {{979-8-3503-2627-7}}, location = {{Guangzhou, China }}, publisher = {{IEEE}}, title = {{{THz-Characterization of Additively Manufactured Spiral Shaped Waveguides}}}, doi = {{10.1109/apcap59480.2023.10469842}}, year = {{2024}}, } @misc{11594, abstract = {{This paper proposes an innovative approach of manufacturing optical fibers using nozzle-mask-aided additive manufacturing. Nozzle-masks ease 3D-printing of optical fibers allowing the manufacturing or drawing of optical fibers of up to 10 μm diameter. These nozzle-masks feature a suction mechanism to prevent clogging of printhead and mask. The extrusion of Polymethyl-methacrylate material through the print-head and nozzle-mask simplifies the rapid prototyping of the optical fibers. }}, author = {{Shrotri, Abhijeet Narendra and Wittenbröker, Christian and Preu, Sascha and Stübbe, Oliver}}, booktitle = {{3D Printed Optics and Additive Photonic Manufacturing IV}}, editor = {{von Freymann, Georg and Herkommer, Alois M. and Flury, Manuel}}, isbn = {{9781510673083}}, issn = {{1996-756X }}, location = {{Strasbourg}}, pages = {{12995 0A}}, publisher = {{SPIE}}, title = {{{Design and simulation of a nozzle-mask for optical fiber 3D-printing}}}, doi = {{10.1117/12.3017000}}, volume = {{12995}}, year = {{2024}}, } @misc{11595, abstract = {{The ability to manufacture complex 3D-objects directly from its CAD model is the important reason why additive manufacturing is being widely used to fabricate cost-efficient prototypes and preferred over conventional manufacturing methods. Moreover, it portrays as a bridging technology to connect different scientific and industrial fields, e.g. Engineering, Medicine, etc. Consequently, additive manufacturing finds its applications in the production of patient-specific orthoses. This paper discusses the development of a pressure sensor based on an optical waveguide principle manufactured using stereolithography apparatus process to embed into a below-knee orthosis. For Orthopedic patients, the below-knee orthosis must be adjusted to the lower leg at regular intervals due to anthropometric changes in patient’s body to achieve proper mobility and correct load. Currently, this alteration relies on the patient’s estimation of support load which is only sub-optimal. Hence, the concept of developing an intelligent orthosis with a novel embedded optical system to monitor the exact support load at the neuralgic is proposed.}}, author = {{Shahane, Akshay Manoj and Shrotri, Abhijeet Narendra and Wittenbröker, Christian and Stübbe, Oliver}}, booktitle = {{3D Printed Optics and Additive Photonic Manufacturing IV}}, editor = {{von Freymann, Georg and Herkommer, Alois M. and Flury, Manuel}}, isbn = {{9781510673083}}, issn = {{1996-756X}}, location = {{Strasbourg}}, publisher = {{SPIE}}, title = {{{Manufacturing of solid core optical waveguide based pressure sensor for 3D-printed below-knee orthosis}}}, doi = {{10.1117/12.3016629}}, volume = {{12995}}, year = {{2024}}, } @misc{11977, abstract = {{Additive manufacturing of lenses offers quick prototyping and characterization. This paper explains the additive manufacturing and characterization of axicon lenses using TOPAS material for Terahertz sensing applications. The beam patterns of additively manufactured axicon lens prototypes are characterized around 0.3 THz with silicon-based THz-camera to evaluate the depth of focus.}}, author = {{Shrotri, Abhijeet Narendra and Krause, Benedikt and Stübbe, Oliver and Pfeiffer, Ullrich and Preu, Sascha}}, booktitle = {{2024 49th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz)}}, issn = {{2162-2035}}, keywords = {{Additives, Prototypes, Three-dimensional printing, Sensors, Lenses}}, location = {{Perth, Australia }}, publisher = {{IEEE}}, title = {{{Evaluation of Additively Manufactured Axicon Lenses Using a THz-Camera}}}, doi = {{10.1109/irmmw-thz60956.2024.10697740}}, volume = {{2024}}, year = {{2024}}, } @misc{11194, abstract = {{Additive Manufacturing (AM) hat die Entwicklung und die Herstellung von Produkten revolutioniert. Durch die Verwendung dieser Technologien ist es möglich kosteneffizient und anforderungsgerecht geringe Stückzahlen herzustellen. Unterschiedliche additive Herstellungstechnologien, wie beispielsweise Fused Layer Modeling (FLM), ermöglichen die Herstellung von Multimaterialkomponenten innerhalb eines Herstellungsschritts. Dies wird erreicht durch die simultane Verwendung von verschiedenen Materialien.Die beim FLM verwendeten Materialien können unterschiedliche Schmelztemperaturen aufweisen. Zudem existieren Materialien, die im Wellenlängenbereich typischer Sensor- und Kommunikationsanwendungen optisch transparent sind. Werden optisch transparente und nicht transparente Materialien mit unterschiedlichen Brechungsindices kombiniert, so ist es möglich lichtführende Strukturen herzustellen. Diese beinhalten alle Vorteile der additiven Herstellungsverfahren.Die lichtführenden Strukturen können in komplexe Komponenten und Systeme wie beispielsweise einem Greifer eines Industrieroboters eingebettet werden. Hier kann der Greifer simultan mit zusätzlicher Sensor- und Kommunikationstechnik gedruckt werden.In diesem Abstrakt werden erste Sensorkomponenten präsentiert. Diese sind mit dem FLM-Verfahren hergestellt worden und es werden Materialien mit unterschiedlichen Transmissionsverhalten verwendet. Zusätzlich werden erste Layout und Herstellungsrichtlinien zur Erstellung von lichtführenden Strukturen mit FLM vorgestellt.}}, author = {{Stübbe, Oliver and Villmer, Franz-Josef and Huxol, Andrea}}, booktitle = {{Rapid.Tech + FabCon 3.D – International Trade Show + Conference for Additive Manufacturing : Proceedings of the 15th Rapid.Tech Conference Erfurt, Germany, 5 – 7 June 2018 }}, editor = {{Kynast, Michael and Eichmann, Michael and Witt, Gerd }}, isbn = {{978-3-446-45811-6 }}, issn = {{978-3-446-45812-3}}, location = {{Erfurt}}, publisher = {{Carl Hanser Verlag GmbH & Co. KG}}, title = {{{3D gedruckte eingebettete lichtführende Strukturen für Sensor- und Kommunikationsanwendungen}}}, doi = {{10.1007/978-3-446-45812-3_30}}, year = {{2023}}, } @misc{10545, abstract = {{Additive manufacturing provides a lucrative alternative for manufacturing of functional prototypes. This paper emonstrates the manufacturing and characterization of hollow core waveguide prototypes with circular cross section using suitable metal and polymers for Terahertz sensing applications. These additively manufactured waveguide prototypes are characterized from 0.1 to 1.25 THz to evaluate the attenuation and coupling losses.}}, author = {{Shrotri, Abhijeet Narendra and Mukherjee, Amlan kusum and Lohöfener, Sven and Springer, André and Stübbe, Oliver and Preu, Sascha}}, booktitle = {{IRMMW-THz 2023 : 48th International Conference on Infrared, Millimeter and Terahertz Waves : 17-22 September 2023, Montreal, Quebec, Canada}}, editor = {{Cooke, David G.}}, isbn = {{979-8-3503-3660-3}}, issn = {{2162-2035 }}, location = {{Montreal, Canada}}, publisher = {{IEEE}}, title = {{{Additive manufacturing and characterization of hollow core metal and topas waveguides for Terahertz sensor systems}}}, doi = {{10.1109/IRMMW-THz57677.2023.10299134}}, year = {{2023}}, } @misc{12888, author = {{Shrotri, Abhijeet Narendra and Stübbe, Oliver}}, location = {{Lemgo}}, title = {{{3D-gedruckte Metall- und Polymerwellenleiter für THz Sensoranwendungen}}}, year = {{2023}}, } @misc{7681, author = {{Shrotri, Abhijeet Narendra and Schneider, Daniel and Flatt, Holger and Stübbe, Oliver}}, publisher = {{Deutsche Forschungsgesellschaft für Automatisierung und Mikroelektronik e.V. (DFAM)}}, title = {{{Visible Light in der Produktion (Abschlussbericht)}}}, year = {{2022}}, } @book{8406, abstract = {{Das Lehr- und Arbeitsbuch entspricht der Einführungsvorlesung der Elektrotechnik an Hochschulen und ist explizit für das Selbststudium konzipiert. Von den physikalischen Grundlagen, elektrotechnischen Grundbegriffen und elektromagnetischen Feldern bis hin zu Fourier-Reihen und transienten Vorgängen werden in 22 Kapiteln grundlegende und vertiefende Vorlesungsinhalte der Elektrotechnik wiedergegeben. Aufgaben, Lösungen und kleinere Zusammenfassungen am Ende jedes Kapitels unterstützen beim selbstständigen Lernen und Erarbeiten der Inhalte. Das Buch führt als Selbststudium leicht lesbar durch die Basis der Elektrotechnik. Das Lernen mit diesem Arbeitsbuch ist in einem Bachelor-Fernstudiengang Elektrotechnik erprobt.}}, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-658-33869-5}}, pages = {{642}}, publisher = {{Springer Vieweg}}, title = {{{Elektrotechnik zum Selbststudium - Grundlagen und Vertiefung}}}, doi = {{ 10.1007/978-3-658-33870-1}}, year = {{2022}}, } @misc{7670, abstract = {{Additive manufacturing (AM) and rapid prototyping process (RPP) have revolutionized the production of 3D objects in the last few decades. RPP has considerably increased the rate of production and the possibility of manufacturing prototypes in the fields of electrical, optical, and mechanical engineering. The manufacturing of optical prototypes including spherical, aspheric, and special kinds of lenses and lens arrays has reformed the fabrication of optical components. In this paper, specifically designed lens array prototypes for application in visible light communication (VLC) are introduced. These lens array prototypes are manufactured using the stereolithography apparatus (SLA) process. These lens arrays are designed to achieve optimal transmission of the light beam for VLC systems. One of the prototypes from the lens arrays contains primarily four spherical lenses and one thicker convex lens and the other contains one fresnel lens as a substitute for thicker convex lens. These lens arrays are further post-processed to achieve the required transparency. These lens array prototypes are tested using laser and LEDs. The ON-OFF keying modulated light beam was transmitted through the lens array at the sender side and focused on the photo-receiver using another lens array at the receiver side which is 200 cm apart. After evaluating these lens prototypes, it can be concluded that with appropriate post-processing and high-resolution stereolithography based manufacturing, a low data rate VLC link can be formed.}}, author = {{Shrotri, Abhijeet Narendra and Beyer, Micha and Schneider, Daniel Johann and Stübbe, Oliver}}, booktitle = {{Laser 3D Manufacturing VIII}}, editor = {{Helvajian, Henry and Gu, Bo and Chen, Hongqiang}}, isbn = {{978-1-5106-4189-1}}, issn = {{1996-756X}}, keywords = {{Additive manufacturing, 3D printing, Stereolithography apparatus, Spherical lenses, Fresnel lenses, Visible light communication}}, location = {{San Francisco }}, publisher = {{Society of Photo-Optical Instrumentation Engineers}}, title = {{{Manufacturing of lens array prototypes containing spherical and fresnel lenses for visible light communications using stereolithography apparatus}}}, doi = {{10.1117/12.2586907}}, volume = {{11677}}, year = {{2021}}, } @misc{7671, abstract = {{Visible-light communication is a promising technology for industrial environments. However, a variety of physical effects may influence the communication quality in this potentially harsh environment: Dust and other particles lead to increased attenuation. Artificial light sources and industrial processes, such as grinding and welding, cause optical cross-talk. A multitude of reflective surfaces can lead to fading due to multi-path propagation. These three aspects are experimentally investigated in exemplary manufacturing processes at five different production sites in order to estimate the relative importance and their specific impact on VLC transmission in industrial areas. Spectral measurements demonstrate the presence of interfering light sources, which occupy broad parts of the visible spectrum. They give rise to flickering noise, which comprises a set of frequencies in the electrical domain. The impact of these effects on the communication is analysed with reference to the maximum achievable channel capacity and data rate approximation based on on-off keying is deduced. It is found that cross-talk by environmental and artificial light sources is one of the strongest effects, which influences the optical, but also the electrical spectrum. It is also observed that industrial areas differ strongly and must be categorised according to the manufacturing processes, which can induce quite a variation of dust and attenuation accordingly.}}, author = {{Schneider, Daniel and Shrotri, Abhijeet Narendra and Flatt, Holger and Stübbe, Oliver and Wolff, Alexander and Lachmayer, Roland and Bunge, Christian-Alexander}}, booktitle = {{Optics express : the international electronic journal of optics / Optica}}, issn = {{1094-4087 }}, number = {{11}}, pages = {{16087--16104}}, publisher = {{Optical Society of America}}, title = {{{Impact of industrial environments on visible light communication}}}, doi = {{10.1364/oe.421757}}, volume = {{29}}, year = {{2021}}, } @inproceedings{7672, abstract = {{Visible light communication (VLC) allows the dual use of lighting and wireless communication systems by modulation of illumination devices. However, to increase the performance, typically, beam-forming measures are taken creating pencil beams, thus contradicting the illumination purpose. In order to optimize the performance trade o between ecient illumination and communication, the switching capabilities of illumination LEDs are examined. Illumination LEDs with standard drivers and without beam-forming show limited applicability for communication purposes as they are not optimized for the necessary switching capability (f  11 MHz) and coherence. Methods to enhance the electrical current by pre-equalisation, biasing, carrier sweeping and current shaping are examined in respect to the illumination LED's communication performance. A novel driver scheme is derived which achieves considerably higher switching frequencies (f  100 MHz) without employing beamforming at the illumination LED. This driver is able to obtain a data rate of up to 200 Mbit/s at a distance of 3.2 m, using on-o keying (OOK) modulation technique. Therefore, it is feasible to apply the LED driver by implementing standardised illumination devices in VLC systems.}}, author = {{Schneider, Daniel and Shrotri, Abhijeet Narendra and Flatt, Holger and Stübbe, Oliver and Lachmayer, Roland}}, booktitle = {{Integrated Optics: Design, Devices, Systems and Applications VI}}, editor = {{Cheben, Pavel and Čtyroký, Jiří and Molina-Fernández, Iñigo}}, isbn = {{978-1-5106-4384-0}}, issn = {{1996-756X}}, keywords = {{Optical Wireless Communication, Visible Light Communication, VLC, Li-Fi, Illumination, Dual-purpose drivers}}, location = {{Online (Prag)}}, publisher = {{SPIE}}, title = {{{Efficient visible light communication drivers using illumination LEDs in industrial environments}}}, doi = {{10.1117/12.2588923}}, volume = {{11775}}, year = {{2021}}, } @misc{7680, abstract = {{In industrial scenarios wireless communication becomes more and more widespread. Radio-frequency technologies are still predominant, but optical wireless communication (OWC) provides many advantages to fulfill the requirements of communication in industrial applications. A survey with industrial users consolidate a list with the most important demands for wireless communication within the field: The results reveal that the current heterogeneous requirements for wireless communication are valid, but highlight the need for license-free, robust and energy efficient wireless communication at rather moderate data rates. These requirements can be met by OWC, but its direct application in industrial environments is often hindered by the harsh conditions, with measurements inter alia indicating specific cross talk by light-emitting processes. In this article, these aspects are discussed one by one in order to obtain a clear perspective about the applicability, the main limitations and potential technologies for OWC and competing approaches in industrial areas. In summary, the application requirements of industrial communication are substantiated, whereas specific limitations and needs for advancement of current OWC systems are derived.}}, author = {{Schneider, Daniel and Shrotri, Abhijeet Narendra and Stübbe, Oliver and Lachmeyer, Roland and Bunge, Christian-Alexander}}, booktitle = {{VDE-ITG Photonische Netze}}, isbn = {{978-3-8007-5555-4}}, location = {{Stuttgart}}, publisher = {{Verband der Elektrotechnik Elektronik Informationstechnik e.V.}}, title = {{{Optical Wireless communication in industrial areas: Potential performance and actual demand}}}, volume = {{297}}, year = {{2021}}, } @misc{7676, author = {{Shrotri, Abhijeet Narendra and Beyer, Micha and Stübbe, Oliver}}, booktitle = {{3D Printed Optics and Additive Photonic Manufacturing II : 6-10 April 2020, online only, France }}, editor = {{von Freymann, Georg and Herkommer, Alois M. and Flury, Manuel}}, isbn = {{978-1-5106-3470-1}}, issn = {{1996-756X}}, keywords = {{Fresnel lenses, Stereolithography apparatus, 3D printing, Photo-polymerization}}, location = {{Strasbourg (online)}}, publisher = {{SPIE}}, title = {{{Manufacturing and analyzing of cost-efficient fresnel lenses using stereolithography}}}, doi = {{10.1117/12.2555367}}, volume = {{11349}}, year = {{2020}}, } @misc{7679, author = {{Shrotri, Abhijeet Narendra and Beyer, Micha and Stübbe, Oliver}}, booktitle = {{ Production engineering and management : proceedings 9th international conference, October 03 and 04, 2019, Trieste, Italy}}, editor = {{Padoano, Elio and Villmer, Franz-Josef}}, isbn = {{978-3-946856-04-7}}, keywords = {{3D printing, stereolithography, optical lens, light forming structures, convex lenses, concave lenses, refraction of light, focal length}}, location = {{Trieste}}, pages = {{227--240}}, publisher = {{Technische Hochschule Ostwestfalen-Lippe}}, title = {{{Evaluation of stereolithograghy processes for the production of lens prototypes}}}, volume = {{2019, 01}}, year = {{2019}}, } @misc{11195, author = {{Schneider, Daniel and Fast, Harry and Flatt, Holger and Jasperneite, Jürgen and Stübbe, Oliver and Heidl, René}}, booktitle = {{Automation 2018 : 19. Leitkongress der Mess- und Automatisierungstechnik : Baden-Baden, 03. und 04. Juli 2018}}, isbn = {{978-3-18-092330-7}}, issn = {{ 0083-5560}}, location = {{Baden-Baden}}, pages = {{273--284}}, publisher = {{VDI Verlag}}, title = {{{Einsatzfähigkeit von optischer Freiraumkommunikation in industriellen Produktionsumgebungen}}}, doi = {{10.51202/9783181023303-273}}, volume = {{2330}}, year = {{2018}}, } @inproceedings{554, abstract = {{Light guiding structures, like optical waveguides or fibers, take an important role in several industries, e.g. communication, sensing, illumination or medical applications. For the latter, it could be very interesting to have the possibility to manufacture problem-adapted structureswith a mechanicalfunctionality andwith additional embedded optical or electrical sensor functionalities.Modern additive manufacturing (AM) technologies like Stereolithography (SLA) or Fused Layer Modeling (FLM) may provide these opportunities.This paper is aimedto figure out the light guiding opportunities of both technologies. For this different kind of structures are built by FLM and SLA. To compare both manufacturing technologies, the layout of each structure is identical for both technologies. After manufacturing, the transmission and the attenuation of the guided light of these structures areanalyzed by measurement.Then the measurement results of the different technologies are compared with each other.}}, author = {{Beyer, Micha and Stübbe, Oliver and Villmer, Franz-Josef}}, booktitle = {{Production engineering and management : proceedings 8th international conference, October 04 and 05, 2018, Lemgo, Germany}}, editor = {{Villmer, Franz-Josef and Padoano, Elio}}, isbn = {{978-3-946856-03-0}}, keywords = {{Additive manufacturing, Embedded optical waveguides, Optical sensors, SLA technology, FLM technology}}, location = {{Lemgo}}, number = {{1}}, pages = {{70--82}}, title = {{{Comparsion of FLM and SLA Processing Technologies Towards Manufacturing of Optical Waveguides for Communicationi and Sensing Applications}}}, year = {{2018}}, } @misc{11134, author = {{Stübbe, Oliver and Huxol, Andrea and Villmer, Franz-Josef}}, booktitle = {{3D Printed Optics and Additive Photonic Manufacturing}}, editor = {{von Freymann, Georg and Herkommer, Alois M. and Flury, Manuel}}, issn = {{1996-756X}}, location = {{Strasbourg, France}}, publisher = {{SPIE}}, title = {{{Applying fused layer modeling technologies to print embedded 3D optical waveguide structures for communication and sensor applications}}}, doi = {{10.1117/12.2306910}}, volume = {{10675}}, year = {{2018}}, } @inproceedings{4836, abstract = {{Today radio based wireless communication technologies offer limited performance, whereas optical wireless com- munication systems (OWC) propose potentially a high performant, scalable communication system conforming to real time conditions. However, current studies imply, that OWCs still lack the necessary performance and robustness level for most wireless applications in industrial production environments. In this approach several types of noises for free-space optical communication systems are empirically analysed in an accredited, exemplary industrial production environment. While the channel noise is usually modelled by the signal to noise ratio it is found that real environments cannot be approximated by the usual static additive white gaussian noise. In this approach the accumulated measurement data represents the spectrum variation of different locations and times relating to different types of noise sources. The implementation in a total channel model allows the optimization of OWC designs like the channel access scheme or the modulation type concerning performance and robustness. Furthermore an additional measurement setup is proposed, capable of measuring and classifying existing noise sources in order to serve the design of OWC systems in industrial production environments.}}, author = {{Schneider, Daniel and Flatt, Holger and Jasperneite, Jürgen and Stübbe, Oliver}}, booktitle = {{Optical Fabrication, Testing, and Metrology VI}}, editor = {{Schröder, Sven and Geyl, Roland}}, isbn = {{978-1-5106-1921-0}}, issn = {{0277-786X}}, location = {{Frankfurt}}, title = {{{Analysis of industrial production environments and derivation of a novel channel model towards optical wireless communication}}}, doi = {{https://doi.org/10.1117/12.2312102}}, volume = {{10692}}, year = {{2018}}, } @book{11196, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-662-53657-5}}, pages = {{138--141}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Gleichstromschaltungen, homogene zeitkonstante Felder}}}, volume = {{1,1}}, year = {{2017}}, } @book{11197, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-662-54516-4}}, pages = {{97}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Schaltungen mit zeitabhängigen Quellen und Sinusquellen}}}, doi = {{10.1007/978-3-662-54517-1}}, volume = {{2,1}}, year = {{2017}}, } @book{11198, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-662-55959-8}}, keywords = {{Elektrisches Feld, Magnetfeld, Inhomogenes Feld, Zeitkonstante, Berechnung}}, pages = {{99}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Inhomogene zeitkonstante Felder}}}, volume = {{1}}, year = {{2017}}, } @book{11255, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-662-56144-7}}, pages = {{205}}, publisher = {{Springer Berlin Heidelberg}}, title = {{{Nichtsinusförmige periodische Schwingungen, transiente Vorgänge}}}, volume = {{3}}, year = {{2017}}, } @book{11266, author = {{Meier, Uwe and Stübbe, Oliver}}, isbn = {{978-3-662-55961-1}}, pages = {{95}}, publisher = {{Springer}}, title = {{{Zeitabhängige Felder}}}, volume = {{2}}, year = {{2017}}, } @inproceedings{573, abstract = {{Additive manufacturing (AM) technologies have not only revolutionized product development and design by enabling rapid prototyping. They also gained influence on production in general, mainly because of their direct manufacturing capabilities. In the context of Industry 4.0 and the related process automation, innovative and advanced production technologies with completely new approaches are required [1]. AM technologies contribute to this with their advantages like freedom of design, cost efficient product individualization, and functional integration. On the other hand, AM still shows shortcomings in exploiting its full potential. Most current AM technologies are only applicable for manufacturing with singular materials. In particular, opportunities for processing of optically or electrically conductive materials are still missing. This paper contributes to the advancement of additive manufacturing of two different material variants or even two completely different materials. A special focus is laid on producing a part that combines mechanical with optical or electrical functionalities in one process step. The ultimate goal is to integrate sensor functionalities into an AM object, e.g. strain gauges. Extrusion processes, predominantly Fused Layer Modeling (FLM), are preferred in this research due to their mechanically simple machine setup in which additional functional materials can be adapted easily to the build process. In a first step, the general manufacturability has been evaluated. Thereafter, the resulting optical transmission properties have been analyzed. Especially the attenuation has to remain below a threshold value to accomplish a minimum signal-to-noise ratio.}}, author = {{Ehlert, Patrick and Stübbe, Oliver and Villmer, Franz-Josef}}, booktitle = {{Production Engineering and Management}}, editor = {{Padoano, Elio and Villmer, Franz-Josef}}, isbn = {{978-3-946856-01-6}}, keywords = {{Additive manufacturing, Embedded optical waveguides, Electrical conductors, Embedded systems, FLM technology, Sensors}}, location = {{Pordenone, Italy}}, number = {{1}}, pages = {{127--136}}, title = {{{Investigation on the Direct Manufacturing of Waveguides and Sensors Using FLM Technology}}}, year = {{2017}}, } @inproceedings{10226, abstract = {{This paper presents a bidirectional optical data transmission system as an enhancement of a contactless power transmission system (CPTS). The latter consists of two separate devices and is able to transmit up to 240W of electrical power using inductive resonant coupling. The optical system consists of two self-developed light-guiding structures and a short-reach free-space optical path. As source and sink of the optical system a light-emitting diode resp. a photodiode with a centroid wavelength of 850nm are used. The optical system is positioned within the CPTS; it transmits the PROFIBUS protocol. Due to the restrictions given by the applications areas of the CPTS, such as air gap up to 5°mm, misalignment up to 2 mm, tilting up to 5 and rotation angle up to 360°, different kinds of light-guiding structures are analyzed by simulation. Based on these results the most promising structures are selected and manufactured. Hereafter the attenuation and the near field characteristic of one light-guiding structure is analyzed. After this, the attenuation based on misalignment, variation of air gap, tilting and rotation between two light-guiding structures are analyzed by measurement. To check whether the requirements of the PROFIBUS has been satisfied by the complete data transmission system, the transient transmission behavior of the system was analyzed by a pseudo-random bit stream. In this paper the most important results of the design, the simulation and the measurement are explained. The presented results demonstrate the ability to design of such systems based on simulations and to evaluate the suitability of various geometries for present and future works.}}, author = {{Neu, Marc and Grünberg, Olaf and Christophliemke, Tobias and Stübbe, Oliver}}, booktitle = {{Optical Interconnects XVII}}, editor = {{Schröder, Henning and Chen, Ray T.}}, issn = {{0277-786X}}, location = {{San Francisco}}, publisher = {{SPIE}}, title = {{{Modeling, simulation and measurement of a bidirectional optical interconnection system for industrial applications}}}, doi = {{10.1117/12.2251014}}, volume = {{10109}}, year = {{2017}}, } @misc{10228, abstract = {{In diesem Beitrag werden die Störeinflüsse für optische Freiraumkommunikation in industriellen Produktionsumgebungen empirisch analysiert und ein Modellierungsansatz abgeleitet. Um drahtlose Kommunikationstechnologien einzusetzen, sind erhebliche Resistenzen gegenüber Störeinflüssen erforderlich, die Visible Light Communication (VLC) bis heute nicht vollständig erfüllt. Anhand von empirischen Messreihen wird in diesem Beitrag nachgewiesen, dass bei der Systemauslegung von VLC, anders als bisher, unterschiedliche Störquellen zu berücksichtigen sind, die orts- und zeitvariante Eigenschaften haben. Auf empirischen Untersuchungen basierend, wird eine alternative Berechnung der gesamten Störquellenleistung vorgeschlagen, die unmittelbar Auswirkung auf das Signal-Rausch-Verhältnis (SNR) und die maximal verfügbare Kanalkapazität hat. Der vorgestellte Ansatz dient dazu VLC-Systeme auch für industrielle Produktionsumgebungen auslegen zu können.}}, author = {{Schneider, Daniel and Flatt, Holger and Jasperneite, Jürgen and Stübbe, Oliver}}, booktitle = {{Komma 2017 : Kommunikation in der Automation : 14.-15.11.2017 : 8. Jahreskolloquium "Kommunikation in der Automation"}}, editor = {{Jumar, Ulrich and Jasperneite, Jürgen}}, isbn = {{978-3-944722-63-4}}, location = {{Magdeburg}}, publisher = {{ Institut für Automation und Kommunikation e.V. Magdeburg, An-Institut der Otto-von-Guericke-Universität Magdeburg }}, title = {{{Entwurf eines Kanalmodells für Visible Light Communication in dynamischen, industriellen Umgebungen}}}, year = {{2017}}, } @inproceedings{10224, abstract = {{Optical interconnects on printed circuit board level are a promising choice to support high bandwidth for short distance interconnects. These interconnects consists of highly multimode step index waveguides with rectangular core cross sections. Therefore ray tracing is an excellent method to determine the optical path parameters, e.g. optical power, ray path lengths and local ray directions. Based on these parameters the step response, the transient transfer function and the coupling behavior can be calculated. Classical ray tracing methods calculates the optical path parameters of each ray by successively computing internal reflections until a termination condition is reached. Therefore the computing time depends on the number of internal reflections. If the optical waveguide consists of cascaded straight and curved segments, e. g. point-to-point interconnects, one can use the analytic ray tracing method to determine the optical path parameters. The whole path parameters of each ray are determined by one analytical computation. The computing time depends on the number of segments. The analytic ray tracing method is unusable to determine ray path parameters of segments with varying core cross sections, e.g. tapers, crossings, splitters and combiners.}}, author = {{Stübbe, Oliver}}, booktitle = {{Optical Interconnects XVII}}, editor = {{Schröder, Henning and Chen, Ray T.}}, issn = {{0277-786X}}, location = {{San Francisco}}, publisher = {{SPIE}}, title = {{{Semi-analytic ray tracing method for time-efficient computing of transmission behavior of PCB level optical interconnects with varying core cross sections}}}, doi = {{10.1117/12.2076931}}, volume = {{9368}}, year = {{2015}}, } @misc{11230, abstract = {{A Proof-of-Concept for a multi-channel WDM board-level optical communications link is under development. This paper is focusing on theoretical and experimental evaluation of thin-glass based nearly single mode graded index optical waveguides with regard to low loss in the 1310nm regime. Results from waveguide characterization will be reported. Waveguide modes are determined theoretically from the measured refractive index profiles. Towards improvement of the robustness of the coupling efficiency against misalignments, investigations on the use of tapered waveguide structures will be presented too.}}, author = {{Schrage, J. and Stübbe, Oliver and Brusberg, L. and Soenmez, Y. and Schroeder, H. and Schuhmann, R.}}, booktitle = {{Optoelectronic Interconnects and Component Integration XI}}, editor = {{Glebov, Alexei L. and Chen, Ray T.}}, isbn = {{ 978-0-8194-8481-9 }}, issn = {{0277-786X}}, location = {{San Francisco, California, United States}}, publisher = {{SPIE}}, title = {{{Evaluation of graded index glass waveguides for board-level WDM optical chip-to-chip communications}}}, doi = {{10.1117/12.876458}}, volume = {{7944}}, year = {{2011}}, } @phdthesis{11200, author = {{Stübbe, Oliver}}, isbn = {{978-3-8322-9139-6}}, keywords = {{Gedruckte Schaltung, Verbindungstechnik, Multimodefaser, Schichtwellenleiter, Geometrische Optik, Übertragungsverhalten}}, pages = {{187}}, publisher = {{Sharker}}, title = {{{Modellierungsverfahren für die zeiteffiziente Simulation von optischen Verbindungen auf Leiterplattenebene}}}, volume = {{33}}, year = {{2010}}, } @misc{11201, abstract = {{Modal noise is an undesired modulation of the guided light intensity in a multimode waveguide. Applying the frequency correlation function the frequency dependence of this noise as well as the bandwidth of a multimode waveguide can be estimated. In this paper the existing model of the frequency correlation function for a waveguide with smoothed dielectric interfaces is enhanced to analyze the influence of surface roughness on the achievable bandwidth. This surface roughness is caused by the manufacturing process of the waveguides.}}, author = {{Stübbe, Oliver and Bierhoff, Thomas and Schrage, Juergen and Mrozynski, Gerd}}, booktitle = {{Wave Optics and Photonic Devices for Optical Information Processing II}}, editor = {{Ambs, Pierre and Beyette, Jr., Fred R.}}, isbn = {{0-8194-5054-5 }}, issn = {{0277-786X}}, location = {{San Diego, California, United States}}, publisher = {{SPIE}}, title = {{{Influence of surface roughness on the bandwidth of optical multimode waveguides analyzed by modal noise theory}}}, doi = {{10.1117/12.505775}}, volume = {{5181}}, year = {{2003}}, } @misc{11130, abstract = {{Modal noise is an undesired modulation of the guided light intensity in a multimode waveguide. Applying the frequency correlation function the frequency dependence of this noise as well as the bandwidth of a multimode waveguide can be estimated. In this paper the existing model of the frequency correlation function for a waveguide with smoothed dielectric interfaces is enhanced to analyze the influence of surface roughness on the achievable bandwidth. This surface roughness is caused by the manufacturing process of the waveguides.}}, author = {{Stübbe, Oliver and Bierhoff, Thomas and Schrage, Juergen and Mrozynski, Gerd}}, booktitle = {{Wave Optics and Photonic Devices for Optical Information Processing II}}, editor = {{Ambs, Pierre and Beyette, Jr., Fred R.}}, issn = {{0277-786X}}, location = {{San Diego, California, United States}}, publisher = {{SPIE}}, title = {{{Influence of surface roughness on the bandwidth of optical multimode waveguides analyzed by modal noise theory}}}, doi = {{10.1117/12.505775}}, volume = {{5181}}, year = {{2003}}, } @misc{11131, abstract = {{To increase the bandwidth of high-performance intrasystem interconnections, optical multimode waveguides can be used. Since the design procedure of optical interconnections has to be widely compatible with conventional design processes, adequate simulation methods are required. This paper presents an improved time domain method for simulating the signal transmission along optical multimode interconnections. The improvements mainly result from the more efficient method for the piecewise approximation of the waveguides step responses by a few exponential functions. The adapted semi-analytical recursive convolution method decreases the computation times.}}, author = {{Gerling, J. and Stübbe, Oliver and Schrage, J.}}, booktitle = {{2003 Design, Automation and Test in Europe Conference and Exhibition}}, isbn = {{0-7695-1870-2}}, issn = {{1530-1591}}, location = {{München}}, publisher = {{IEEE Comput. Soc}}, title = {{{Improved time domain simulation of optical multimode intrasystem interconnects}}}, doi = {{10.1109/date.2003.1253758}}, year = {{2003}}, }