Patent ID: 8154976

Claim:
An optical pickup used for performing recording, reproduction, or deletion of information with respect to two types of optical recording media A and B having different used wavelengths, the optical pickup comprising: a light source A that emits light having a wavelength of λ1; a light source B that emits light having a wavelength of λ2 that is greater than λ1 ; a converging unit that converges the light emitted from the light source A and the light emitted from the light source B onto recording surfaces as accessed objects of the recording media; a branch unit that is arranged on a light path between the converging unit and the light sources A and B and branches a return light flux through the converging unit; a light receiving unit that receives the return light flux branched by the branch unit at a predetermined light receiving position; and a reflecting wavelength plate that is arranged on the light path between the converging unit and the branch unit; wherein the reflecting wavelength plate includes a substrate, a reflecting film laminated on the substrate, and a sub-wavelength concavo-convex structure that is laminated on the reflecting film and has a pitch less than or equal to a wavelength of λ1, and the reflecting wavelength plate is configured so that a filling factor and a groove depth of the sub-wavelength concavo-convex structure are determined so as to add a phase difference obtained by (kπ)/8, where k is an integer, to the light emitted from the light source A and the light emitted from the light source B.