| 摘要 |
PURPOSE:To realize a high density recording by irradiating a rotating optical recording medium with a laser light having a wavelength smaller than 500nm and forming an amorphous recording part on a recording layer in a crystalline state. CONSTITUTION:By irradiating an optical recording medium rotating at a linear velocity larger than 10m/s with a laser light having a wavelength smaller than 500nm through an objective lens with a numerical aperture larger than 0.55 and an amorphous recording part is formed on a recording layer in a crystalline state. For example, the disk is made to rotate at a linear velocity of 15m/s, an argon laser beam with a wavelength 488nm is converged and projected by means of an objective lens of NA 0.60 and recording/reproducing is performed. When recording is executed with a frequency of 22.5MHz, a CNR (signal versus noise ratio) becomes 48dB and a recording code length becomes 0.33mum. This is about 2.3 times of a linear recording density of the current optical disk. |
