| 摘要 |
PROBLEM TO BE SOLVED: To provide an integrated optical pickup compatible with CD/DVD that can realize detection of a tracking error in the DPP method compatible with a DVD-RAM. SOLUTION: This optical pickup is provide with a 3-beam generating diffraction grating that distributes a 1st laser beam with a 1st wavelength λ1 and a 2nd laser beam with a 2nd wavelength λ2 to 3 emission lights respectively and a hologram element that is divided at least into 1st and 2nd regions within the same plane and distributes a reflected light from a recording medium toward a light receiving element substrate. The 1st and the 2nd regions of the hologram element and the 3-beam generating diffraction grating are configured such that the diffracted light of a 1st side beam, which is one of ±1st-order diffracted lights distributed by the 3-beam generating diffraction grating, by the 1st region resulting from the 1st laser beam is overlapped on the diffracted light of a 2nd side beam, which is the other of the ±1st-order diffracted lights distributed by the 3-beam generating diffraction grating, by the 2nd region on the light receiving element substrate. |
