Objective optical system of optical pick up, optical pick-up device and optical information recording/reproducing apparatus

摘要

An objective optical system for use in an optical pickup apparatus, comprises an aberration correcting element having at least two phase structures of a first and second phase structures; and a light converging element to converge the first light flux emitted from the aberration correcting element onto an information recording plane of the first optical disk and to converge the second light flux emitted from the aberration correcting element onto an information recording plane of the second optical disk; wherein the second phase structure refrains at least one of a change in the light converging characteristic of the objective optical system due to a change in the wavelength of the first light flux and a change in the light converging characteristic of the objective optical system due to a change in environmental temperature.