| 摘要 |
PURPOSE:To efficiently obtain a high output power at the time of recording and to improve the regenerative signal quality by synthesizing a laser beam having the different wavelength and designing suitably the wavelength dependency of the transmissivity of a polarizing beam splitter. CONSTITUTION:The emitting beams of lasers 1 and 11 having the different wavelength are synthesized by an optical element 13 and made incident on an optical beam splitter 14. When the wavelengths of the lasers 1 and 11 are suitably set for the design wavelength of the splitter 14, the P polarizing face can obtain about 40% transmissivity, an S polarizing face can obtain 0% transmissivity to a laser 1 and can obtain about 100% transmissivity to a laser 11. Thus, at the time of recording or erasing, the lasers 1 and 11 are simultaneously driven and a large spot power synthesized on the face of a magneto- optical disk 10 is obtained. At the time of reproduction, only the laser 11 is driven and the reproduction is performed. Then, the high quality recording and reproducing can be efficiently performed. |
