Light-receiving element, optical head, optical recording/reproducing apparatus, and method of optical recording and reproduction

摘要

The invention relates to a light-receiving element for receiving a reflection of laser light irradiated to a rotating multi-layer recording medium having a plurality of information recording layers stacked one over another and for converting the light into an electrical signal, an optical head having the element for recording information in the multi-layer recording medium or reproducing information recorded therein, and an optical recording/reproducing apparatus and a method of optical recording and reproduction. The invention provides a light-receiving element, an optical head, an optical recording/reproducing apparatus, and a method of optical recording and reproduction which make it possible to eliminate a noise component superimposed on reflected light from a multi-layer recording medium to reproduce an RF signal of high quality. The light receiving element receives a reflection of laser light irradiated through an objective lens to a rotating multi-layer recording medium having a plurality of information recording layers stacked one over another through a return path optical system and converts the reflected light into an electrical signal. The element has a first light-receiving section having a circular light-receiving region and a second light-receiving section disposed adjacent to the outer circumference of the first light-receiving section in the form of a circle concentric therewith.