Patent ID: 7355933

Claim:
An optical system for an optical pickup device in which light is emitted from a light source, reflected by an optical disk, and detected by a light receiving device, the optical system comprising: a diffraction grating optically coupled to the light source; a polarizing hologram optically coupled to said diffraction grating, said polarizing hologram diffracting either only p-polarized light or only s-polarized light, said polarizing hologram only diffracts light polarized in a direction perpendicular to a direction of polarization of at least a portion of light emitted from the light source; a quarter-wave plate optically coupled to said polarizing hologram, said quarter-wave plate converting linearly polarized light into circularly polarized light and/or converting circularly polarized light into linearly polarized light; wherein, in operation, the entirety of the light emitted from the light source impinges upon the optical disk via said diffraction grating, said polarizing hologram, and said quarter-wave plate, and said light is reflected by the optical disk and is caused to pass through said quarter-wave plate and said polarizing hologram such that, in said light, at least a light of Â±1 impinges upon the light receiving device and light of order 0 does not return to the light source.