| 摘要 |
PROBLEM TO BE SOLVED: To provide a small sized optical pickup device whose light utilization efficiency is high and by which high exit power is obtained. SOLUTION: Outgoing light emitted by a laser beam source 2 placed on a silicon substrate 8 transmits a hologram element 3 consisting of a translucent plane 4 and a diffraction grating 10, an NA is converted by an NA conversion lens 5, transmits the polarizing film 6a of a polarizing beam splitter 6, and is condensed on a magneto-optical disk via a collimator lens 7 and an objective lens not shown by a figure. Light reflected by the polarizing film 6a of the polarizing beam splitter 6 of return light from the magneto-optical disk is reflected by a reflecting surface 6b, is branched into two light by a Wollaston prism 9 and is made incident on a light receiving element group 11. On the other hand, light transmitting the polarizing beam splitter 6 is branched into two light by the hologram element 3 and is made incident on light receiving element groups 40, 41. |
