Optical pickup device, recording and reproducing apparatus and gap detection method

摘要

An optical pickup device and an optical recording and reproducing apparatus are suitable for use with a near-field optical recording and reproducing system. An optical pickup device comprises an objective lens composed of a solid immersion lens (SIL), the objective lens having a numerical aperture greater than 1, a beam splitter 102 for reflecting both of a p-polarized light component and an s-polarized light component of reflected lights from an optical recording medium when the optical pickup device irradiates the optical recording medium with a bundle of rays in a predetermined polarized state from a light source through the objective lens to detect a component in the polarized state perpendicular to the polarized state of reflected light obtained when a distance between the surface of this optical recording medium and the flat surface portion of the solid immersion lens (SIL) is zero to produce a signal corresponding to the distance between the surface of the optical recording medium and the flat surface portion of the solid immersion lens, a dividing means 110 for dividing incident light into a p-polarized light component and an s-polarized light component reflected by the beam splitter 102 and a photo-detecting means 120 for separately detecting the p-polarized light component and the s-polarized light component divided by the dividing means 110.