Scattering Optical Elements: Towards complete control of light propagation on the wavelength scale

The challenge of making artificial photonic crystals has developed many top of the art fabrication methods. Many of these methods such as lithography or micromanipulation (Aoki et al., 2003), are so complete that they are not only restricted for crystal fabrication, but also being able to introduce very complex defects into otherwise ordered structures. Taking advantage of this freedom of design one can push this to its extreme creating optimized free-form structures by breaking the symmetry and introducing an excessive number of defects. Within this framework, with the goal of complete control of light propagation, we have established a new type of optical devices named scattering optical elements (SOE) (Hakansson et al., 2005). SOEs are inverse designed optical components where each scatterer is placed in an optimized position with respect to a chosen functionality. The universality of the design approach makes it very straight forward to do optical component ´design on demand´.