| 摘要 |
<p>An optical pickup apparatus for recording or reproducing data on a signal recording surface of a high-density optical medium that has the signal recording surface and at least one substrate is disclosed. The apparatus has an optical module for generating and emitting beams and receiving reflected beams from an optical medium; and a solid immersion lens (SIL) arranged on an optical path between the optical module and the optical medium, having a first surface being planar and facing the substrate of the optical medium, and a second surface being aspherical and facing the optical module, so that the SIL may be nearly in contact with the substrate of the optical medium. The beams from the optical module enter the SIL, and are then focused through the substrate onto the signal recording surface without a condenser objective lens. When collimated beams are emitted from the optical module and a refractive index of the SIL is identical with that of the substrate of the optical recording medium, the second surface of the SIL is an ellipsoidal surface. When divergent beams are emitted from the optical module and a refractive index of the SIL is identical with that of the substrate of the optical recording medium, the second surface of the SIL is a Cartesian oval.</p> |
