Lasers out of the 3D printer: The future of optical manufacturing begins in Niedersachsen

The scientists of the innovation network GROTESK want to manufacture optics and optomechanical assemblies using Additive Manufacturing. (Photo: LZH)

Since July 2018, the project team from Hannover and Clausthal cooperates closely (from left to right): Prof. Dr.-Ing. Volker Wesling (CZM), Prof. Dr.-Ing. Roland Lachmayer (LUH), Dr. Dietmar Kracht (LZH), Prof. Dr.-Ing. Henning Ahlers (HsH), Katharina Rettschlag (LUH), Robert Bernhard (CZM), Philipp Neef (CZM), Marius Lammers (HsH), Fabian Kranert (LZH), Jana Budde (LZH) and Tobias Grabe (LUH). (Photo: LZH)

"Manufacturing optics in 3D opens up unprecedented design opportunities" said Dr. Dietmar Kracht from the LZH. (Photo: LZH)

Tension-free printed optic for use in a 3D printed laser system. (Photo: LZH)

On November 19th, 2019, in Hannover, Niedersachsen presented "GROTESK - the future of optics manufacturing". The four partners in the innovation network "GROTESK - Generative Production of Optical, Thermal and Structural Components" presented research approaches with which optical systems can be manufactured in completely different ways in the future.

Manufacturing optical systems using 3D printing – this is the goal of the team of the Gottfried Wilhelm Leibniz Universität Hannover (LUH), the Clausthaler Zentrum für Materialtechnik (CZM), the Hochschule Hannover - University of Applied Sciences and Arts (HsH) and the Laser Zentrum Hannover e.V. (LZH). "Today, we will hear from the partners of the GROTESK project which applications can arise from this exciting field of research," said Dr.-Ing. Stefan Kaierle, project manager of Niedersachsen ADDITIV and Executive Director at the LZH when he welcomed the approx. 80 guests.

Then, the deputy project manager, Dr.-Ing. Gerrit Hohenhoff, introduced Niedersachsen ADDITIV, which offers a wide range of events in addition to research, development and consulting for small and medium-sized enterprises (SMEs).

Digitization challenges optics manufacturing
"Innovation happens in our heads. I am delighted to see many young guests here today ", said the coordinator of the consortium, Prof. Dr.-Ing. Roland Lachmayer (LUH). GROTESK is researching how optical systems can be digitally constructed and converted into real assemblies by means of Additive Manufacturing. The researchers can already print internal structures for improved cooling of a laser. With a digital twin, the team at the LUH simulates the thermomechanical properties of a 3D component and can thus model the manufacturing process in advance. More efficient cooling systems enable higher output powers without thermal losses - a prerequisite for more powerful laser systems.

Material properties are the key
"We have to choose materials wisely and adjust properties such as the melting point and the surface properties," emphasized Prof. Dr.-Ing. Volker Wesling (CZM). The CZM attaches particular importance to both the connection during the direct printing of a material on an optical component and to the resulting thermal influences. The high thermal load in this process can lead to increased tensions, which sometimes lead to the breakage of the optics. However, this can be prevented with adapted material systems.

Flexible and applicable machine concepts
Optical systems often consist of different types of materials. "We print metal, glass and polymers and would like to be able to change the materials with little effort," explained Prof. Dr.-Ing. Henning Ahlers (HsH) the challenge to the system technology. The solution: A coaxial laser deposition welding head that splits the laser beam and rejoins it later. In this way, the component can be processed independently of the direction, and the different materials can be fed flexibly and automatically.

Laser out of the 3D printer
"We are still a long way from automated laser production. But the concepts presented today make a major contribution to our ability to automate many systems in the future." said Dr. Dietmar Kracht from the LZH. The LZH team is already able to directly print optics into a medium in a tension-free way. This process can be automated, saving a manual step in laser assembly. In the future, GROTESK intends to digitally construct and print entire laser systems.

During the breaks in the showroom, the guests informed themselves about the research works and first results of GROTESK and made new contacts during the technical discussions.

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Laser Zentrum Hannover e.V. (LZH)
As an independent, non-profit research institute, the Laser Zentrum Hannover e.V. (LZH) stands for innovative research, development and consulting. The LZH is supported by the Niedersachsen Ministry of Economic Affairs, Employment, Transport and Digitalisation and is dedicated to the selfless promotion of applied research in the field of photonics and laser technology. Founded in 1986, over 170 employees are now working for the LZH.

The focus of the LZH lies on the fields of optical components and systems, optical production technologies, and biomedical photonics. Interdisciplinary cooperation between natural scientists and mechanical engineers makes innovative approaches to challenges from the most different areas possible: from the development of components for specific laser systems to process developments for the most diverse laser applications, for example for medical technology or lightweight construction in the automotive sector. Eighteen spin off companies have emerged from the LZH up to now. Thus, the LZH has created a strong transfer between fundamental science, application oriented research, and industry.

Niedersachsen ADDITIV – Zentrum für Additive Fertigung
Niedersachsen ADDITIV is dedicated to research additive manufacturing processes, to further develop them for widespread use in industry and to help small and medium-sized enterprises (SMEs) in Lower Saxony to integrate the new technologies into their production processes. For this purpose, four partners have joined forces in Niedersachsen ADDITIV: the Laser Zentrum Hannover e. V. (LZH), the Institute for Integrated Production Hannover gGmbH (IPH), the Deutsche Messe Technology Academy GmbH and the LZH Laser Akademie GmbH. The center is supported by Lower Saxony’s Ministry of Economics, Labour, Transport and Digitalization. More information at

The project acronym GROTESK stands for “Generative Fertigung optischer, thermaler und struktureller Komponenten“ (generative manufacturing of optical, thermal and structural components). The project is being carried out in the innovation network under the leadership of the Gottfried Wilhelm Leibniz Universität, together with the Clausthaler Zentrum für Materialtechnik, the Hochschule Hannover - University of Applied Sciences and Arts and the LZH.