High density near-field optical recording (invited) (abstract)

Near-field scanning optical microscopy (NSOM) has been used to image and record domains in thin-film magneto-optic (MO) materials (e.g., a Co/Pt multilayer). In this technique, a subwavelength-sized source or detector of visible light is placed in close proximity to a sample and raster scanned to read or write data on a scale inaccessible to traditional lens based systems. The technique, therefore, represents a hybridization of conventional magnetic and MO storage technologies. In the imaging mode, resolution of 30–50 nm has been consistently obtained, whereas in the recording mode, domains down to −60 nm have been written reproducibly. Data densities of −45 Gbits/in.2 have been achieved, well in excess of current magnetic and MO methods. A brief analysis of speed and other issues indicates that the technique may represent a viable alternative to these and other methods for anticipated high density data storage needs.