| 摘要 |
PURPOSE:To enable the recording and reproducing of a high density and high capacity by a short-wavelength light source by using a laser beam consisting of two beams; a beam for recording and erasing and a beam for reproducing. CONSTITUTION:The two-beam system of the beam for recording and erasing and the beam for reproducing is used. A longwavelength semiconductor laser 2 which is the light source of a high output and long wavelength is used as the laser beam for recording and erasing. For example, the max. laser power on the medium surface at 830nm wavelength is 15mW. On the other hand, the short-wavelength semiconductor laser 3 which is the light source of a short output and short wavelength is used as the laser beam for reproducing. For example, the the max. laser power on the medium surface at 430nm wavelength is 1mW. |
