Gerd-Albert Hoffmann

Gerd-Albert Hoffmann
Laser Zentrum Hannover e.V. | LZH

Master of Science

About

31
Publications
1,891
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134
Citations
Citations since 2017
25 Research Items
132 Citations
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20172018201920202021202220230102030

Publications

Publications (31)
Conference Paper
Ta 2 O 5 and SiO 2 films coated by rotary atomic layer deposition were studied. Investigations proved low absorption 3.1 ppm, respectively 6.0 ppm as well as uniformity 1.55 % and 2.71 % for growth rates up to 0.18 nm/sec. (e-mail: l.kochanneck@lzh.de ).
Conference Paper
To unlock the benefits of thin-film filters, produced by means of ion beam sputtering, for compact, hybrid integrated optical systems, we have implemented a sacrificial-substrate approach to create high-precision, miniaturized, substrate-free filters.
Article
Optical networks can carry significantly higher data rates than their equivalent electrical systems. Because of their unique properties and constraints, optical networks have their own design rules. In this paper, an algorithm for the optimization of optical networks is presented. In addition, an optimized optical decimal-binary converter is flexog...
Article
To produce polymer optical fibers in research environments, a flexible cladding material-application process is required. Further, to functionalize the waveguide, the fiber core-production step needs to be separated from the cladding application, contrasting conventional polymer optical fiber production processes. In this study, we developed a solu...
Article
Full-text available
This paper introduces a new manufacturing process for vertical interconnect accesses (VIA). In contrast to industrially established VIA metallization technologies, the presented approach takes place without any chemical plating by combining copper ink and epoxy insulator coating with CO2 laser processing for VIA drilling and copper ink sintering. T...
Conference Paper
Printing polymer optical waveguides by means of combined printing processes has proven to be a challenging but effective way of producing waveguides with a loss less than 0.3dB/cm. In order to evaluate the optical performance of the produced waveguides, optical simulations have been carried out. In this work we show the influence on the optical per...
Article
Full-text available
Processing technology to improve the manufacturing of thermoelectric generators (TEGs) is a growing field of research. In this paper, an adaptable and scalable process comprising spray-coating and laser structuring for fast and easy TEG manufacturing is presented. The developed process combines additive and subtractive processing technology towards...
Article
Full-text available
The innovations in smart packaging will open up a wide range of opportunities in the future. This work describes the processing of additive manufactured and planar integrated polymer optical waveguides for use in smart packaging products. The previously published combination of flexographic and Aerosol Jet printing is complemented by thermoforming...
Conference Paper
This paper analyzes an approach for additively manufacturing polymer optical waveguides. The production process includes flexographic printing of conditioning lines (5 μm height) on a substrate, which are used as guiding barriers in the subsequent printing of the optical core. The core is additively printed (up to 50 μm in height) with an aerosol j...
Article
Full-text available
An efficient and low-cost approach to manufacture Opto-Mechatronic Interconnect Devices will be obligatory to handle the strongly increasing amount of data. The presented approach is based on a flexographic printing process. To adjust the transferred material the printing form is functionalized by means of laser-induced structures using an ultrasho...
Conference Paper
Recent fabrication methods print polymer optical waveguides (POWs) on three-dimensional carriers. The special geometry of the POWs enables the realisation of an optical ray splitter which is simulated by raytracing using a new bisection-algorithm.
Conference Paper
This paper shows the modeling, simulation and production of polymer optical waveguides using the OPTAVER process. The additive manufactured multimode waveguides with their typical cross-section of a circle shape are of low cost and high-performance.
Article
Considering the increasing amount of data for communication and infotainment applications, fabrication of optical networks and bus systems is a challenging task for production engineering. A two-step manufacturing process for polymer optical waveguides is presented. By improving the highly efficient flexographic printing technology by laser functio...
Article
The research for new production chains in the field of waveguide fabrication is a challenging task. Realizing a cost efficient manufacturing process allows integrating optical data communication in arbitrary structures as for example the wing of an airplane or the car body. The production chain described in this paper contains the design, simulatio...
Article
Full-text available
Networks of optical waveguides allow for data transmission and sensing applications. Therefore, this technology is a key element for the integration of intelligent systems and structural health monitoring. Optical waveguides are the essential backbone to connect these structures.
Conference Paper
This paper describes the effect of laser structured printing forms that are used in flexographic printing processes. This adaption is developed to optimize the conditioning of flexible polymer substrates for the downstream application of optical waveguides.
Conference Paper
The optical data transfer is considered as the future of signal transfer due to its various advantages compared to conventional copper-based technologies. The Aerosol Jet Printing (AJP) technology offers the opportunity to print materials with high viscosities, such as liquid transparent polymer adhesives (epoxy resins), on almost any possible subs...
Conference Paper
As a tribute to the continuously increasing volume of data traffic, optical waveguides have become a serious alternative to electrical circuitries. The potential of precise spaceresolved strain measurements or the capacity to transmit very large amounts of data are two examples of the beneficial use of optical systems. Apart from the general advant...
Conference Paper
The printing of polymer optical waveguides is part of the current research in functional printing technology. Optimizing the transmission quality and the resolution are key objectives to establish integrated optical data transmission in the industry. The manufacturing of multimode waveguides presented in this work is accomplished by a combination o...
Article
Full-text available
Due to increasingly more stringent environmental and safety regulations as well as the globally increasing but locally different customer demands, automanufacturers are in search of measures to meet these requirements. In order to do so, research and development departments particularly focus on sustainable, light weight solutions. Based on materia...

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