Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
CPP 92.4: Vortrag
Donnerstag, 19. März 2020, 10:30–10:50, TOE 317
Mass-producible microoptical elements by injection compression molding and focused ion beam structured titanium molding tools — •Simon Ristok1, Marcel Röder2, Simon Thiele3, Mario Hentschel1, Thomas Günther2, André Zimmermann2, Alois Herkommer3, and Harald Gießen1 — 14th Physics Institute and Research Center SCoPE, University of Stuttgart, Germany — 2Hahn-Schickard, Stuttgart, Germany — 3Institute of Applied Optics and Research Center SCoPE, University of Stuttgart, Germany
Injection molded polymer is the material of choice for micro-optics used in mass producible devices such as smartphones or optical sensors. For feature sizes on the micrometer scale the molding tools are usually fabricated by nickel electroplating on a silicon master, which was previously structured by electron beam lithography and subsequent etching. In total, two inversion steps are necessary to transfer the structure from the silicon master to a plastic polymer part. Here, we introduce an alternative method that requires only a single inversion step. An extremely robust titanium molding tool is directly structured with high precision by focused ion beam milling. We demonstrate the fabrication of Fresnel lenses with 100 µm diameter and a maximum structure height of 1 µm. The inverse Fresnel lens structured into the titanium is transferred to polymer by injection compression molding, enabling rapid mass replication. We show that the optical performance of the molded Fresnel lenses is in good agreement with simulations, rendering our approach suitable for applications which require compact and high quality optical elements in large numbers.