Multi-photon polymerization by means of Nanoscribe’s direct laser writing systems allows for the fabrication of complex and replicable 2.5D structures. Polymer micro-optics can be used as moulds for replication or masters for pattern transfer. The key advantage compared to 2.5D gray scale lithography or 2D UV-exposure and subsequent reflow techniques is clear: Arbitrary complex shapes can be fabricated in one single step – may it be refractive optics such as arrays of aspheres, diffractive optics such as Fresnel lenses or even stacked micro-lenses. In addition to this, negative-tone resists may be used which are less sensitive to the development process compared to positive-tone resists - thus allowing for high reproducibility of the complete process. Furthermore, micro-optics of up to several 100 µm height can be fabricated with optimal resolution: No necessity to leverage the height via Reactive Ion Etching (RIE) into the underlying substrate! Please click on the thumbnails to open a detailed view as well as explanations.