Patent ID: 8154962

Claim:
An optical pickup comprising, a first laser source for emitting light beams having respective wavelength λ 1 and wavelength λ 2 shorter than λ 1 , a first objective lens for focusing the light beams of wavelengths λ 1 and λ 2 emitted by the first laser source on an information recording surface of an information recording medium, a second laser source for emitting a light beam having a wavelength λ 3 shorter than λ 2 , a second objective lens for focusing the light beam of wavelength λ 3 emitted by the second laser source on the information recording surface of the information recording medium, and single light intensity monitoring element for monitoring light intensities of the light beams of wavelengths λ 1 , λ 2 and λ 3 emitted by the first and second laser sources, wherein the single light intensity monitoring element is configured to monitor the light intensities of parts of the light beams emitted by the first laser source which parts are in an effective diameter of the first objective lens, and the light intensity of a part of the light beam emitted by the second laser source which part is prevented from being in an effective diameter of the second objective lens.