| 摘要 |
PURPOSE:To provide the optical information recording and reproducing device with which high-density recording exceeding the limit of former information recording density is possible. CONSTITUTION:A laser beam 21 emitted from a laser beam source 20 is diffracted to plural different directions by an optical diffraction element 100 and after the plural diffracted light beams emitted from the optical diffraction element 100 are collimated to plural beams by a collimating lens 12, the parallel beams are transmitted through a beam splitter 3 and the interference thereof is caused in the same position on a rotary disk medium 6 by an objective lens 5. As a result, a narrow isolated intensity peak is formed by the interference (multiwave interference) in a condensing position and a pit corresponding to one bit is formed by this isolated intensity peak. Consequently, the recording of the narrow pits exceeding the diffraction threshold in the case of condensing of the laser beam effectively only by the objective lens is possible and the higher density of the information recording density on the optical recording medium is easily attained. |
