Thin Film Filters

Actively tunable optical components are essential for micro-optical devices. This project encompasses the design, the manufacturing and the characterization of active super-prism structures for focal length tuning. Chief goal is the realization of micro-optical components that allow quick and easy focal length tuning in the range of 100 μs.

As it is known from photonic crystals, highly dispersive super-prism structures amplify tuning effects. On the basis of these insights, the project team aims at combining the super-prism effect with active polymer material, such as dielectric elastomers or ferro-electric polymers. Here, the scientists can fall back on extensive preliminary research on highly dispersive super-prism structures. In addition, they aim at making the manufacturing process reliable and reproducible with the help of thin-film technology.

The one-dimensional super-prism structures will be designed such that the effective direction of the path of light depends on the angle of incident light and the voltage applied to the polymer. (see diagram) Integrated into a convergent light path, these components facilitate the active tuning of the focal length.

The novel filter components can easily be integrated into complex systems and adjusted to individual requirements, which makes them attractive to both scientific approaches regarding the micro eye. In the cluster-eye design, every single facet could be tuned individually. In the single aperture design, these filters can enhance the image quality.

Team Leaders:

• Professor Martina Gerken
  Christian-Albrechts-University Kiel
  Integrierte Systeme und Photonik
  email: gerken@tf.uni-kiel.de
• Professor Uli Lemmer
  Karlsruhe University (TH)
  Lichttechnisches Institut
  email: uli.lemmer@lti.uni-karlsruhe.de