3D printing of polymer optics

Summary form only given. Additive manufacturing based on multiphoton polymerization has set new standards for three-dimensional microfabrication. Due to its sub-micrometer spatial resolution, the technique provides the surface smoothness and shape accuracy required for high-quality optical elements. Almost arbitrary shapes can be created from 3D digital models. Technological improvements have sped up our 3D printers by more than a factor 100 while preserving its accuracy and resolution. High-precision scan optics in combination with material research allow for fast and precise solidification of photopolymers and simultaneously secure mechanical stability, structural conformity and optically smooth surfaces. Sophisticated embedded writing strategies additionally made the fabrication time drop to a fraction allowing for the fabrication of micro-photonic components with tailored shapes in millimeter to centimeter size. We discuss the printing challenges connected with diffractive elements, photonic color materials, photonic crystals, micro lens arrays and other types of freeform optics. Other examples are components like aspheric optics, cones, wedges and micro-pyramids that are demonstrated with RMS roughness of less than 10 nm. Arrays with 100% filling factor, as well as hemispheres with vertical walls have been fabricated. These examples - either used directly after printing or as a master for molding and casting - are typical elements of micro-optical systems and serve as toolbox for our customers in the field of photonics.