Optics Design

Fraunhofer ILT offers its clients comprehensive expertise in customized geometric-optical laser systems. Among others, it focuses its research and development on beam shaping, fiber coupling as well as simulating the generation and propagation of radiation.

Given power density distributions can be generated with customized freeform optics through the redistribution of power through refraction and reflection. For this purpose, Fraunhofer ILT develops complex optimization algorithms with which virtual prototypes are created, the properties of which are then checked with simulation software. Freeform optics are used, for example, in LED lighting or in laser systems. Even materials with special properties are used for other optical systems. Thanks to the high refractive index of 2.4 and the high thermal conductivity, diamond allows, for example, dimensions of laser optics to be reduced drastically. Together with the Fraunhofer institutes IAF and IPT, Fraunhofer ILT has developed a laser cutting head that is 90% lighter than conventional components compared with glass optics and is very suitable for laser cutting processes.

The range of services offered by Fraunhofer ILT cover R&D in design and simulation, experimental studies on laboratory models, the development of industry-related, certified prototypes and comprehensive technology consulting as well as market research and feasibility studies.

Optics Design

• Imaging and non-imaging optical systems for coherent and incoherent systems
• Micro optical systems
• λ from UV to IR and average power up to multi kW
• Tolerance analysis
• Design for production and assembly

Opto-mechanical Design

• FE analysis of opto-mechanical assemblies
• Calculation and correction of laser-induced thermal lenses
• Mechanical design of high power optics
• Fast scanning systems for high power lasers

Tailored Intensity Profiles

• Beam transformation
• 1D and 2D homogenization
• Application-specific optics for pumping, hardening, polymer welding, brazing and cleaning

Assembly of Optical Systems

• Production measurement technology for optical systems
• Algorithms and methods for automated alignment and assembly
• Qualification of optical systems

Esser, D., Giesberts, M., Erben, B., Nyga, S., Kasemann, R., Wührer, C., Hahn, S., Leyendecker, M., Eßer, J., Wirz, W., Klein, S., Traub, M., Klein, J., Brandenburg, W., Luttmann, K., Mohr, D., Pérez Prieto, L., Hoffmann, H.-D,
Optomechanical design of a 150 mJ single frequency UV laser for the AEOLUS-2 mission.
International Conference on Space Optics — ICSO 2022, 3-7 October 2022, Dubrovnik, Croatia. Proceedings Volume 12777, International Conference on Space Optics — ICSO 2022; 127770N (2023).
https://doi.org/10.1117/12.2688830

Grubert, N., Prochnau, M., Stollenwerk, J., Holly, C.,
Fiber-based sensor for combustion chamber monitoring: manufacturing challenge.
SPIE OPTO, 28 Jan - 3 Feb 2023, San Francisco, California, United States. Proceedings Volume 12434, MOEMS and Miniaturized Systems XXII; 124340O (2023)
http://dx.doi.org/10.1117/12.2647501

Fu, C., Kemmerling, M., Stollenwerk, J., Holly, C.:
Ansätze für die Entwicklung von optischen Systemen mittels bestärkenden Lernens.
124. Jahrestagung der Deutschen Gesellschaft für angewandte Optik e.V., 30.05.2023-03.06.2023, Berlin.
DGaO-Proceedings, B10,(2 S.) (2023)

Fu, C., Stollenwerk, J., Holly, C.:
Reinforcement learning for guiding optimization processes in optical design.
SPIE Optical Engineering + Applications, 2022, San Diego, California, United States.
Proceedings Volume 12227, Applications of Machine Learning 2022; 1222709 (2022)
http://dx.doi.org/10.1117/12.2632425

Grubert, N., Lange, O., Stollenwerk, J., Holly, C.,
Optomechanische Toleranzangaben aus dem Optikdesign nach ISO-GPS-Norm.
123. Jahrestagung der Deutschen Gesellschaft für angewandte Optik, 7.-11.Juni 2022, Pforzheim. DGaO-Proceedings 123_A32 (2022)

Lüttgenau, B., Panitzek, D., Danylyuk, S., Brose, S., Stollenwerk, J., Loosen, P., Holly, C.:
Design of an efficient illuminator for partially coherent sources in the extreme ultraviolet.
APPLIED OPTICS 61(11), 3026-3033 (2022)
http://dx.doi.org/10.1364/ao.452204 (Open Access)

Barnowski, D., Dahmen, M., Farkas, T., Petring, D., Petschke, U., Pootz, M., Schäl, R.:
Multifunctional laser processing with a digital twin.
12th CIRP Conference on Photonic Technologies [LANE 2022], 4-8 September 2022, Fürth, Germany - (2022)
https://doi.org/10.1016/j.procir.2022.08.091

Hesker, M., Fu, C., Heinrichs, M., Stollenwerk, J., Loosen, P.:
Precise and fast autofocus measuring device for high-resolution high-speed pupillometry.
CLEO, Conference on Lasers and Electro-Optics Applications and Technology 2021,9–14 May 2021, San Jose, California US. OSA Technical Digest (Optica Publishing Group, 2021), paper AW3T.4, (2021)   https://doi.org/10.1364/CLEO_AT.2021.AW3T.4

Grubert, N., König, G., Stollenwerk, J., Loosen, P.:
Ring-Shaped Conoscopic Holography for Distance and Tilt Measurement.
Conference on Lasers and Electro-, 09.05-14.5.2021, online only. OSA Technical Digest (Optical Society of America, 2021), paper ATh4Q.4 (2021)
https://doi.org/10.1364/CLEO_AT.2021.ATh4Q.4

Lantzsch, T., Traub, M., Westphalen, T., Tenbrock, C., Schleifenbaum, J. H.:
Laser powder bed fusion of stainless steel 316L using a combination of
high-power diode laser and galvanometer scanner.
SPIE LASE, 2021, Online Only. Proceedings Volume 11677, Laser 3D Manufacturing VIII; 116770M (2021)
https://doi.org/10.1117/12.2573128

Lüttgenau, B., Brose, S., Choi, S., Panitzek, D., Danylyuk, S., Lebert, R., Stollenwerk, J., Loosen, P.:
Design and realization of an industrial stand-alone EUV resist qualification setup.
SPIE Photomask Technology + EUV Lithography, 2020, Online Only. Proceedings Volume 11517, Extreme Ultraviolet Lithography 2020; 115171F (2020)
http://dx.doi.org/10.1117/12.2572803

Hofmann, O., Chemerenko, O., Finger, J., Eifel, S., Stollenwerk, J., Loosen, P.:
Highly dynamic positioning of individual laser beams in a multi-beam system for laser surface processing.
Procedia CIRP 94, 812-816 (2020)
https://doi.org/10.1016/j.procir.2020.09.123

Grubert, N., König, G., Stollenwerk, J., Loosen, P.:
Methodik zur kostenbasierten Toleranzbudgetfestlegung optomechanischer Systeme.
121. Jahrestagung der Deutschen Gesellschaft für angewandte Optik e. V.(DGaO), 02. - 06. Juni 2020. BremenDGaO-Proceedings, A22 (2 S.) (2020)

Hofmann, J., Bonhoff, T., Stollenwerk, J., Loosen, P.:
Auslegungsmethodik für Kunststoffoptiken in Laseranwendungen.
121. Jahrestagung der Deutschen Gesellschaft für angewandte Optik e. V.(DGaO), 02. - 06. Juni 2020. BremenDGaO-Proceedings, A19, (2 S.), (2020)

König, G., Grochowski M., Eckert, M., Jakobczak, F., Stollenwerk, J., Kowalewski, S., Loosen P.:
Apparat zur automatisierten Justage optischer Systeme.
121. Jahrestagung der Deutschen Gesellschaft für angewandte Optik e. V.(DGaO), 02. - 06. Juni 2020. BremenDGaO-Proceedings, A23 (2 S.) (2020)

Traub, M., Holly, C., Di Meo, A., Arntz, D,, Hesker, M., Hoffmann, D., Nebel, C., Poprawe, R.:
Diamond lenses enable ultra-compact and lightweight laser processing heads.
90th Laser Materials Processing Conference, 10.-11.12.2018, Japan. Proceedings of the 90th Laser Materials Processing Conference, 135-138, (2018)

Holters, M., Dirks, S., Stollenwerk, J., Loosen, P.:
Automated and model-based assembly of an anamorphic telescope.
SPIE OPTO, 22 February 2018, San Francisco, California, United States. Proc. SPIE 10538, Optical Interconnects XVIII, 105380U (2018), 1-10 (2018)
https://doi.org/10.1117/12.2291910

Prochnau, M., Holzbrink, M., Wang, W., Holters, M., Stollenwerk, J., Loosen, P.:
Measurement methods to build up the digital optical twin.
SPIE LASE, 27 January-1 February 2018, San Francisco, California, United States. Proceedings Volume 10513, Components and Packaging for Laser Systems IV; 105131I (2018)
https://doi.org/10.1117/12.2290002

Prochnau,M., Stollenwerk, J., Loosen, P.:
Approach towards the digital optical twin.
International Optical Design Conference - IODC 2017,09-13 July 2017 Denver United States. Proc. SPIE 10590, International Optical Design Conference 2017, 1059021, (6 S.), 1-6 (2017)
https://doi.org/10.1117/12.2287492

Traub, M., Holly, C., Hoffmann, D., Widmann, C., Zuerbig, V., Nebel, C.:
Synthetic Mono-Crystalline Diamond Lenses for High Power Laser Materials Processing Applications.
OSA Optical Design and Fabrication Congress, IODC 2017, 09 - 13 July 2017, Denver, Colorado, United States.Optics InfoBase Conference PapersVolume Part F56-OFT 2017, 2017, 1-3 (2017)
https://doi.org/10.1364/OFT.2017.OTu3B.3

König, G., Chen, C., Holters, M., Stollenwerk, J.H., Loosen, P.:
Comparison of Different Methods for Robustness Estimation of Simple Lens Systems.
OSA Optical Design and Fabrication Congress, IODC 2017, 09 - 13 July 2017, Denver, Colorado United States.Optics InfoBase Conference PapersVolume Part F51-IODC 2017, 2017, 1-2 (2017) https://doi.org/10.1364/IODC.2017.IM3A.6

Holters, M., Stollenwerk, J., Loosen, P.:
Ermittlung der Montagereihenfolge für Präzisionsoptiken.
118. DGaO (Deutsche Gesellschaft für angewandte Optik e. V.) Jahrestagung. 6.-10. Juni 2017 in Dresden. DGaO-Proceedings 2017. B 31., 1-2 (2017)

Prochnau,M., Stollenwerk, J., Loosen, P.:
Approach towards the Digital Optical Twin.
International Optical Design Conference 2017. Denver, Colorado United States
9–13 July 2017, paper ITh3A.1(2 S.), 1-2 (2017)
https://doi.org/10.1364/IODC.2017.ITh3A.1

Pütsch, O., Stollenwerk, J., Loosen, P.:
Integrated optical design for highly dynamic laser beam shaping with membrane deformable mirrors.
SPIE LASE, 2017, San Francisco, California, United States. Proceedings Volume 10090, Laser Resonators, Microresonators, and Beam Control XIX; 1009010 (2017)
https://doi.org/10.1117/12.2256127

Holly, C., Traub, M., Hoffmann, D., Widmann, C., Brink, D., Nebel, C., Gotthardt, T., Sölzbir, M. C., Wenzel, C.:
Monocrystalline CVD-diamond optics for high-power laser applications.
SPIE LASE, 2016, San Francisco, California, United States. Proceedings Volume 9741, High-Power Laser Materials Processing: Lasers, Beam Delivery, Diagnostics, and Applications V; 974104 (2016)
https://doi.org/10.1117/12.2213601

Bonhoff, T., Büsing, L., Stollenwerk, J., Loosen, P.:
Modeling of optical aberrations due to thermal deformation using finite element analysis and ray-tracing
SPIE Optical Systems Design, 2015, Jena, Germany. Proceedings Volume 9626, Optical Systems Design 2015: Optical Design and Engineering VI; 96261V (2015)
https://doi.org/10.1117/12.2190879

Esser, D., Staasmeyer, J.-H., Weitenberg, J., Rußbüldt, T., Sartorius, T., Hoffmann, H.-D.:
Fused-silica mirror substrates with laser-microstructured openings with reduced chipping
CLEO_Europe 2015. 21-25 June 2015 in Munich. CE_10_3. (2015)

Traub, M., Hoffmann, D., Hengesbach, S., Loosen, P.:
Automatic design of multi-lens optical systems based on stock lenses for high power lasers.
PROCEEDINGS OF SPIE 9293, SPIE, 1-8 (2014)
https://doi.org/10.1117/12.2074508

Thombansen, U., Hermanns, T.:
In-situ measurement of the focal position in one and ten micron laser cutting
Proceedings 33rd Int. Congress on Applications of Lasers & Electro-Optics (ICALEO), October 19-23, 2014, San Diego, USA,
Paper 179, ISBN 9781940168029 (4 S.) (2014)
https://doi.org/10.2351/1.5063049

Thombansen, U., Hermanns, T.: Molitor, T., Pereira, M., Schulz, W.:
Measurement of cut front properties in laser cutting
Physics Procedia  56, 885-891 (2014)
https://doi.org/10.1016/j.phpro.2014.08.107

Thombansen, U., Hermanns, T., Stoyanov, S.:
Setup and maintenance of manufacturing quality in CO2 laser cutting
Procedia CIRP 20, 98 – 102 (2014)
https://doi.org/10.1016/j.procir.2014.05.037

Thombansen, U., Ungers, M.:
Illumination for process observation in laser material processing
Physics Procedia  56, 1286-1296 (2014)
https://doi.org/10.1016/j.phpro.2014.08.053

Thombansen, U., Ungers, M.:
Cognition for robot scanner based remote welding
SPIE LASE, 2014, San Francisco, California, United States. Proceedings Volume 8963, High-Power Laser Materials Processing: Lasers, Beam Delivery, Diagnostics, and Applications III; 89630N (2014)
https://doi.org/10.1117/12.2040275

Pütsch, O., Bahrenberg, L., Loosen, P.:
Opto-mechatronisches System zur Erzeugung prozessangepasster Intensitätsverteilungen für die Lasermaterialbearbeitung
Mechatronik 2013, Aachen, 06.-08.03.2013, VDI, (9 S.), (2013)

Pütsch, O., Temmler, A., Stollenwerk, J., Willenborg, E., Loosen, P.:
Active optical system for laser structuring of 3D surfaces remelting
SPIE LASE, 2015, San Francisco, California, United States. Proceedings Volume 9356, High-Power Laser Materials Processing: Lasers, Beam Delivery, Diagnostics, and Applications IV; 93560U (2015)
http://dx.doi.org/10.1117/12.2076051

Crump, P., Hengesbach, S., Witte, U., Hoffmann, H.-D., Erbert, G., Tränkle, G.:
High-power diode lasers optimized for low-loss smile-insensitive external spectral stabilization
IEEE Photon. Technol. Lett. 24, Nr. 8, 703-705, (2012)
https://doi.org/10.1109/LPT.2012.2187277

Gatej, A., Wasselowski, J., Loosen, P.:
Thermo-optical (TOP) analysis by coupling FEM and ray tracing
SPIE Photonics Europe, 2012, Brussels, Belgium. Proceedings Volume 8429, Optical Modelling and Design II; 84290E (2012)
https://doi.org/10.1117/12.921533

Gatej, A., Wasselowski, J., Loosen, P.:
Using Adaptive Weighted Least Squares Approximation for Coupling Thermal and Optical Simulation
Applied Optics 51/28, 6718–6725 (2012)
https://doi.org/10.1364/ao.51.006718

Gatej, A., Richman, A., Pütsch, O., Loosen, P.:
Thermo-Optical (TOP) analysis of transmissive elements for laser-systems 
SPIE Optical Engineering + Applications, 2012, San Diego, California, United States. Proceedings Volume 8490, Laser Beam Shaping XIII; 84900C (2012)
https://doi.org/10.1117/12.929213

Pütsch, O., Loosen, P.:
Electro-optically actuated liquid-lens zoom 
SPIE Photonics Europe, 2012, Brussels, Belgium. Proceedings Volume 8429, Optical Modelling and Design II; 842906 (2012)
https://doi.org/10.1117/12.922631

Hengesbach, S., Witte, U., Traub, M., Hoffmann, D.:
Simulation and analysis of volume holographic gratings integrated in collimation optics for wavelength stabilization 
SPIE LASE, 2011, San Francisco, California, United States. Proceedings Volume 7918, High-Power Diode Laser Technology and Applications IX; 79180A (2011)
https://doi.org/10.1117/12.877538

Funck, M., Loosen, P.:
Estimating the performance gain of selectively assembled optical systems
53. Int. Wissenschaftliches Kolloquium, Techn. Univ. Ilmenau. CD-ROM, pp. 160-161, (2008)

Schnitzler, C., Hambuecker, S., Ruebenach, O., Sinhoff, V., Steckman, G., West, L., Wessling, C., Hoffmann, H.-D.:
Wavelength stabilization of HPDL array: fast-axis collimation optic with integrated VHG
Proc. SPIE 6456, 1-7, (2007)
Lasers and Applications in Science and Engineering, 2007, San Jose, California, United States. Proceedings Volume 6456, High-Power Diode Laser Technology and Applications V; 645612 (2007)
https://doi.org/10.1117/12.698334

Traub, M., Hoffmann, H.-D., Plum, H.-D., Wieching, K., Loosen, P., Poprawe, R.:
Homogenization of high power diode laser beams for pumping and direct applications
Lasers and Applications in Science and Engineering, 2006, San Jose, California, United States. Proceedings Volume 6104, High-Power Diode Laser Technology and Applications IV; 61040Q (2006)
https://doi.org/10.1117/12.645260

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