Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges

article Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges published yes Tomasz Blachowicz author Guido Ehrmann author Johannes Fiedler author Reinhard Kaschuba author Andrea Ehrmann author 2237760000-0003-0695-3905 Institut für Technische Energie-Systeme project Freeform optics belong to the increasingly important elements in optical research and industry, which pose several challenges regarding design and highly precise manufacturing. First being used in cameras and for focusing, nowadays freeform optics are used in a broad range of applications, from lighting to LiDAR, from endoscopy to photovoltaics, and from astronomical instruments to quantum cryptography. Designing freeform optics can be based on different theories and methods. Fabrication is possible by mechanical methods, such as diamond turning or high-precision milling, often followed by different polishing techniques, as well as laser-based techniques, mainly applying different lithographic techniques. Here, we give an overview of recent design and optimization methods, production methods used during the last years, and applications of freeform optics, including the possibility to combine freeform optics with tunability for different applications. We describe the opportunities of new applications as well as common problems and give an outlook towards future directions of research and development. https://www.hsbi.de/publikationsserver/download/6901/6902/_2026_Blachowicz_Micro6_35.pdf application/pdfno MDPI AG2026 eng photopolymerizationtunable micro-optical freeform elementstwo-photon polymerizationmultiphoton lithographydirect laser writingdiamond turning Micro 2673-8023urn:nbn:de:hbz:bi10-6901710.3390/micro6020035 62 T. Blachowicz, G. Ehrmann, J. Fiedler, R. Kaschuba, and A. Ehrmann, “Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges,” Micro, vol. 6, no. 2, 2026. @article{Blachowicz_Ehrmann_Fiedler_Kaschuba_Ehrmann_2026, title={Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges}, volume={6}, DOI={<a href="https://doi.org/10.3390/micro6020035">10.3390/micro6020035</a>}, number={235}, journal={Micro}, publisher={MDPI AG}, author={Blachowicz, Tomasz and Ehrmann, Guido and Fiedler, Johannes and Kaschuba, Reinhard and Ehrmann, Andrea}, year={2026} } Blachowicz, T., Ehrmann, G., Fiedler, J., Kaschuba, R., & Ehrmann, A. (2026). Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges. Micro, 6(2). <a href="https://doi.org/10.3390/micro6020035">https://doi.org/10.3390/micro6020035</a> Blachowicz, Tomasz ; Ehrmann, Guido ; Fiedler, Johannes ; Kaschuba, Reinhard ; Ehrmann, Andrea: Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges. In: Micro Bd. 6, MDPI AG (2026), Nr. 2 Blachowicz, Tomasz, Guido Ehrmann, Johannes Fiedler, Reinhard Kaschuba, and Andrea Ehrmann. “Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges.” Micro 6, no. 2 (2026). <a href="https://doi.org/10.3390/micro6020035">https://doi.org/10.3390/micro6020035</a>. T. Blachowicz, G. Ehrmann, J. Fiedler, R. Kaschuba, A. Ehrmann, Micro 6 (2026). Blachowicz T, Ehrmann G, Fiedler J, Kaschuba R, Ehrmann A. Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges. Micro. 2026;6(2). doi:<a href="https://doi.org/10.3390/micro6020035">10.3390/micro6020035</a> Blachowicz, Tomasz, et al. “Freeform Micro-Optical Elements—Recent Production Techniques, Opportunities and Challenges.” Micro, vol. 6, no. 2, 35, MDPI AG, 2026, doi:<a href="https://doi.org/10.3390/micro6020035">10.3390/micro6020035</a>. 69012026-05-11T20:35:02Z2026-05-12T05:18:08Z