Optical pickup apparatus and diffractive optical element for optical pickup apparatus

摘要

An optical pickup apparatus, includes: first-third light sources emitting first-third light fluxes respectively; a diffractive optical and; an objective optical system having a light converging element, wherein the diffractive optical element includes a first area whose center is on an optical axis; a second area formed in a ring-shape and arranged outside of the first area; a third area formed in a ring-shape and arranged outside of the second area; and the first-third areas have different optical properties each other for the first-third light fluxes, the third area does not form two light fluxes among the first-third light fluxes passing the third area and the light converging element into a converged spot on the information recording surfaces of corresponding disks.