| 摘要 |
PURPOSE:To provide a magneto-optical pickup device which is miniaturized and reduced in cost and sufficiently reduces the diameter of a beam spot on a recording medium and increases a recording density. CONSTITUTION:This device is provided with a t east a semiconductor laser 3, a beam splitter 5 which seperates an reciprocating path to a magneto-optical recording medium 1 and a photodetector 8 by which a reflected light from the magneto-optical recording medium 1 seperated at the relevant beam splitter 5 is received on a common semiconductor substrate 2, a concave lens 5d is formed on the part of the beam splitter 5 on which an outgoing light from the semiconductor laser 3 is incident a deflection hologram 6 is provided between an objective lens 7 and the beam splitter 5 or between the splitter 5 and the photodetector 8, the outgoing light from the semiconductor laser 3 is expanded by the concave lens 5d and is made incident on the objective lens 7 and simultaneously the deflection component of the reflected light from the magneto-optical recording medium 1 is seperated by the deflection hologram 6 and the light is received by the photodetector 8. |
