| 摘要 |
PURPOSE:To enable high density recording with a reproducing spot diameter being smaller than a recording spot diameter by recording information with a fundamental wave of light emitted from one laser light source and reproducing the information with the n-th higher harmonics. CONSTITUTION:The subject device is provided with an n-th higher harmonics generator 2 constituted for phase matching with a wavelength of the fundamental wave in the case of low power of the fundamental wave emitted from the laser light source 1. Then, the information is recorded by the fundamental wave of light emitted from one laser light source 1, while the information is reproduced by the n-th higher harmonics, so that since the information is reproduced by the n-th higher harmonics, the reproducing spot can be made smaller than the recording spot. By this method, even when the recording spots are close to each other, the information can be reproduced, and hence high recording densification can be achieved by a close-set amt. of the recording spots. |
