| 摘要 |
PURPOSE:To miniaturize a device and to reduce the positional deviation among parts by unification to improve the reliability by constituting a semiconductor laser, two beam splitters, and photodetectors on a substrate as one body. CONSTITUTION:The laser light from a semiconductor laser 1 is reflected by a polarizing separation film 105 for light branching of a beam splitter 2 of an optical path branching means and is thrown to a recording medium 70, and the reflected light from this medium 70 is transmitted through the film 105. When this transmitted light is made incident on a beam splitter 3 of a polarizing means, the reflected light is separated into p-polarized light and s-polarized light and they are made incident on photodetectors 7 and 8 respectively because the intersection between the junction face of the beam splitter 3 and the reflection or transmission face of the beam splitter 3 and the line connecting the light emission point of a laser 4 and the spot center of the reflection face of a beam splitter 2 due to the laser are inclined at 45 deg.. By this constitution, the laser 1, two beam splitters 2 and 3, and photodetectors 7 and 8 are unified on the substrate to miniaturize the optical head device, and the positional deviation among parts is reduced to improve the reliability. |
