| 摘要 |
Optical pickup 24 for operation in the far-field and in the near-field mode comprising a movable part 26 having an objective lens 2 comprising a solid immersion lens 4 and a multifocal lens 6, which are both disposed on a common optical axis A. The multifocal lens 6 comprises a central zone 8 and a peripheral zone 10 being circumferential to the central zone 8. The peripheral zone is adapted to constitute an optical system for a far-field mode. The central zone 8 of the multifocal lens 6 together with the solid immersion lens 4 are adapted to constitute an optical system for a near-field mode. The solid immersion lens and the multifocal lens are adapted to be moved in unison. A method for operating an optical pickup 24 comprises a first approach to a surface 21 of an optical storage medium 22 with the movable part 26 to reach a far-field working distance DF based on a focus control using an optical system for working in the far-field mode, and a subsequent approach to the surface 21 of the optical storage medium 22 which is performed by lowering the far-field working distance DF to a smaller near-field working distance NF.
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