| 摘要 |
An optical head apparatus includes a light source, an optical modulation unit, an objective lens, a reflected beam condensing unit, and a photodetection unit. The light source emits a light beam. The optical modulation unit modulates one of a light intensity and a phase in a section of the light beam from the light source and adjusts a generation position of a side lobe light beam of the light beam. The optical modulation unit has at least a first strip-like light-shielding area inclined by a first predetermined angle with respect to a vertical axis in the section of the light beam. The objective lens focuses the light beam from the optical modulation unit to form a small spot on a recording medium. The reflected beam condensing unit condenses a reflected beam from the small spot on the recording medium. The photodetection unit detects the reflected beam from the reflected beam condensing unit to reproduce information.
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