TY - JOUR A1 - Adomavičiũtė-Grabusovė, Sonata A1 - Hinkel, Jonas A1 - Usenov, Iskander A1 - Novikov, Alexander S. A1 - Sakharova, Tatiana A1 - Döhler, Torsten A1 - Geißler, Ute A1 - Feliksberger, Elena A1 - Artyushenko, Viacheslav T1 - Microstructuring of the end-surface for silver halide polycrystalline fibers to suppress Fresnel reflection JF - Optical Materials Express N2 - Silver halide polycrystalline infrared fibers (PIR) have unique properties such as excellent transmittance in the spectral range from 3 to 17 µm, while also being highly flexible, non-toxic, and non-hygroscopic. They are used in industry and medicine for CO2-laser power delivery, flexible infrared imaging, and remote process spectroscopy. While PIR fibers possess a quite low attenuation (0.1-0.5 dB/m) in the 8-12 µm range, their total transmittance is limited by significant Fresnel reflections at the fiber end faces due to the high refractive index of silver halide (>2.1). Functionalization of these surfaces with specially designed Anti-Reflective Microstructures (ARMs) enables a striking enhancement of fiber transmittance. In this work, direct imprinting (or embossing) of microstructures to fiber ends and their profiling with a microstructured knife was applied to fabricate such ARMs. The resulting two-dimensional Moth-eye microstructures and one-dimensional microgrooves at the PIR-fiber ends enable to an increase of fiber transmittance in a broadband range of (5-17 µm) as well as to reach up to 20% improvement for PIR-fiber laser cables used for power delivery of CO2-lasers at 10.6 µm. KW - effective refractive index KW - fresnel reflection KW - infrared fiber KW - infrared imaging KW - quantum cascade semiconductor laser KW - refractive index Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-15549 VL - 12 IS - 1 SP - 34 EP - 48 PB - Optica Publishing Group ER - TY - CHAP A1 - Döhler, Torsten A1 - Böhme, Andrea A1 - Hofmann, Mandy A1 - Neumann, Jens A1 - Bochem, Reinhard A1 - Foitzik, Andreas A1 - Geißler, Ute T1 - Mikrogalvanische Kennzeichnung als Kopierschutz T1 - Electroplated Micro-Labelling as Copy Protection T2 - Open Conference Proceedings N2 - In order to achieve good product quality in electroplating, disturbance variables such as the "dog bone" effect must be avoided. In this work, this approach was used to develop a method for marking as product protection. With a defined structure and optimal parameters, it is possible to deposit unique visually non-differentiable layers on suitable substrates. The deposited layers and their local distribution were characterized by confocal laser microscopy, X-ray fluorescence analysis and laser interference measurements and analyzed qualitatively as well as quantitatively. It thus provides interested parties with an essentially traditional process that can lead to new innovations with the chosen approach. N2 - Um eine gute Produktqualität in der Galvanik zu erreichen, müssen Störgrößen wie zum Beispiel der "Hundeknochen"-Effekt vermieden werden. In dieser Arbeit wurde dieser Ansatz genutzt, um eine Methode zur Kennzeichnung als Produktschutz zu entwickeln. Mit definiertem Aufbau und optimalen Parametern ist es möglich, auf geeigneten Substraten, unikale visuell nicht differenzierbare Schichten abzuscheiden. Die abgeschiedenen Schichten und deren lokale Verteilung wurden mit Hilfe konfokaler Lasermikroskopie, Röntgenfluores-zenzanalyse und Laserinterferenzmessungen charakterisiert und qualitativ als auch quantitativ analysiert. Interessenten stellt es damit ein im Grunde traditionelles Verfahren zur Verfügung, das mit dem gewählten Ansatz zu neuen Innovationen führen kann. Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:526-opus4-17624 VL - 2 SP - 157 EP - 161 PB - TIB Open Publishing ER -