A near-field, interferometric optical microscopy system includes: a beam splitter positioned to separate an input beam into a measurement beam and a reference beam; a mask positioned to receive the measurement beam, the mask comprising at least one aperture having a dimension smaller than the wavelength...http://www.google.de/patents/US6753968?utm_source=gb-gplus-sharePatent US6753968 - Optical storage system based on scanning interferometric near-field confocal microscopy