OPTICAL DISC HAVING A SUPER RESOLUTION NEAR-FIELD STRUCTURE, CONCERNED WITH RECORDING OR GENERATING MARKS WITH A SIZE LESS THAN A RESOLUTION OF A LASER BEAM

摘要

PURPOSE: An optical disc is provided to record or regenerate marks with a size less than a resolution of a laser beam by adopting a super resolution near-field structure so that it prevents instability or irregularity of regenerated signals caused by insufficient crystallization. CONSTITUTION: The disc comprises a base plate(31), a metal oxide mask layer(33), a phase change record assistance layer(35) and dielectric layers(32,34,36). The base plate(31) has a high transparency feature for a wave length of a record laser. The metal oxide mask layer(33), made of metal oxide like AgOx or PtOx, has a super resolution near-field structure. The phase change record assistance layer(35) is made of a crystallization material. The dielectric layers(32,34,36) are formed among the base plate(31), the metal oxide mask layer(33), and the phase change record assistance layer(35).