In history any field of activity shows periods that are characterized by evolutionary, revolutionary and stagnating
moments, respectively. Especially in optics the 17th, 19th, and 20th century can be considered as revolutionary periods that changed our insight dramatically. However, the often observed opinion that a discipline is already completed was always revised by new facts that broadened our knowledge about the certain field. For instance, in modern optics the discovery of the wave front reconstruction principle (holography) and the implementation of the light amplification by stimulated emission in the laser pushed the further development of the field in an outstanding way. Nevertheless, a lot of questions are looking for an answer. Particularly, in order to justify its role as an enabling technology for most of the key technologies optics has to follow strictly the enormous requirements in spatial resolution, robustness, reliability and traceability. Since it is far beyond the claim of this contribution to address all these problems we concentrate our view
on modern approaches of resolution enhancement only.