| 摘要 |
<p>[Problem] To provide an optical pickup device wherein, in the cases where three laser beams having different wavelengths are outputted from one semiconductor laser apparatus, the spot diameters of the laser beams having respective wavelengths can be increased on the light receiving surface of an optical detector. [Solution] A semiconductor laser (101) has light emitting sections (101a, 101b, 101c) housed in a same package, and outputs BD light, DVD light and CD light in the same direction. A diffractive optical element (DOE) (109) makes the optical axis of the BD light accord with the optical axis of the DVD light such that the BD light having a highest numerical aperture, and the DVD light having a second highest numerical aperture overlap on an optical detector (111). Consequently, the size of the sensor of the optical detector (111) can be increased, and the spot diameters of each laser light can be increased.</p> |
