| 摘要 |
PURPOSE: To sufficiently reduce return light quantity being a noise occurrence cause of a semiconductor laser by providing a light attenuator of a light energy attenuation means. CONSTITUTION: This optical head 3 is provided with a semiconductor laser oscillator 9 of a light generation means, the light attenuator 11f of the light energy attenuation means, a polarizing beam splitter prism 11b of a light splitting means and photodetectors 7, 8 of a light detection means. The semiconductor laser oscillator 9 outputs light for recording/reproducing information on/from an optical disk 1 with the energy so that a return light noise becomes nearly minimum. The light attenuator 11f attenuates the output energy of the light from the semiconductor laser oscillator 9 to the output required for recording/ reproducing the optical disk 1. The polarizing beam splitter prism 11b transmits through the light attenuated by the light attenuator 11f, and splits the reflected light of the light, and the photodetectors 7, 8 detect the split light. Thus, the return light quantity is reduced sufficiently, and the influence of a noise is reduced by attenuating a laser output to a level suitable for recording/ reproducing with the light attenuator 11f even when the output from the laser oscillator 9 is high. |
