Patent ID: 7075865

Claim:
An optical pickup for forming a light-collecting spot on an information recording plane to optically record/reproduce information, said pickup comprising: a first light source for emitting light at a first wavelength Î» 1 ; a second light source for emitting light at a different, second wavelength Î» 2 from the first wavelength Î» 1 , such that Î» 1 <Î» 2 ; light collecting means for forming a light-collecting spot on an information recording plane of a first recording medium from the light at the wavelength Î» 1 and forming a light-collecting spot on an information recording plane of a second recording medium from the light at the wavelength Î» 2 , the first and second recording media having different substrate thicknesses; and a diffractive element disposed between the first and second light sources and the light collecting means, wherein the diffractive element is of a combination type fabricated by combining two different raw materials at a combining plane which is shaped as a diffraction grating, and the light collecting means has an aberration corrected for the light at the first wavelength Î» 1 .