| 摘要 |
In order to (i) reduce astigmatism due to a diffraction grating capable of compensating light intensity distribution of a light beam emitted by a light source and (ii) simplify fabrication processes, an optical pickup device of the present invention includes: a semiconductor laser 1 ; a collimator lens 4 ; a diffraction grating 3 capable of changing light intensity distribution of a light beam emitted by the semiconductor laser 1 ; a polarizing beam splitter 5 for causing a laser beam reflected by an optical disc 8 to be directed in a direction different from a direction of the light beam emitted by the semiconductor laser 1; and a parallel plate 2 for compensating astigmatism due to the diffraction grating 3, the parallel plate 2 being provided between the semiconductor laser 1 and the collimator lens 4 so as to be inclined to an optical axis of the semiconductor laser 1.
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