Improving the lateral resolution in case of structuring technical surfaces by application of solid immersion lenses (SILs)

To improve the diffraction efficiency of DOEs, it is necessary to use multistage structures. However, the lateral resolution of structures that are produced by direct laser writing are restricted to half of the used wavelength due to diffraction limitation. By applying optical nearfield techniques this limitation can be overcome. These techniques are used within systems such as Scanning Nearfield Optical Lithography (SNOL) or Liquid - or Solid Immersion Lens Systems. Different nearfield techniques will be presented. Using the example of confocal lithography technique the enhancement and optimisation of the appropriate setup will be reported.