| 摘要 |
In an optical pickup device which is compatible with two light beam having two wavelengths, a beam shaping mirror is arranged which has an incident surface and a reflecting surface that are disposed in non parallel relation, and makes light intensity distribution of the light beam emitted from a light source that has the light intensity distribution in a shape of ellipse, close to a circular shape by reflecting the light beam coming into the incident surface by the reflecting surface. A diffraction grating is formed on the reflecting surface of the beam shaping mirror, at least one of the two light beams having different wavelengths emitted from the light source is diffracted by the diffraction grating, and directions of optical axes of the two light beams which are output from the beam shaping mirror are made substantially the same. |
