Patent ID: 7369467

Claim:
An optical pickup that performs recording on or reproducing from an optical disc having lands and grooves in which information can be recorded to and/or reproduced from, the optical pickup comprising: a light source; an optical path changer for causing a beam emitted by the light source to propagate toward the optical disc; an objective lens for focusing the beam incident from the optical path changer onto the optical disc; a polarization holographic optical element (HOE) for splitting the beam reflected from the optical disc into diffracted beams; and a photodetector for photoelectrically converting diffracted beams, wherein the polarization HOE has a pattern designed to generate different astigmatisms in the left and right halves of the polarization HOE in a tangential direction and to divide plus and minus first-order beams in a radial direction, and the photodetector comprises a first light-receiving portion for receiving a zero-order beam and second and third light-receiving portions that are disposed on either side of the first light-receiving portion in the tangential direction and respectively receive the plus and minus first-order beams, wherein each of the first through third light-receiving portions is divided into four (2 by 2) sections.