| 摘要 |
<p>An optical pickup device includes a beam shaping mirror. The mirror has a first optical surface on which a wavelength selection film is formed and a second optical surface on which a diffraction grating is formed. The wavelength selection film transmits a first laser beam and reflects a second laser beam. Light intensity distribution of the first laser beam is converted from an elliptic shape to a circular shape by reflecting the first laser beam transmitted by the wavelength selection film and input to the beam shaping mirror by the diffraction grating, then transmitting it by the wavelength selection film and outputting it from the beam shaping mirror. The diffraction grating diffracts the first laser beam in order that directions of the first and second laser beams which are output from the beam shaping mirror become the same.</p> |
