| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an objective lens which can suppress fluctuation of diffraction efficiency due to a change of a using wavelength to a minimum, in an objective lens for an optical pickup device which collects diffracted light generated by an optical path difference giving structure onto the information recording surface of an optical information recording medium as a spot, and to provide an optical pickup device using such an objective lens. <P>SOLUTION: The total diffraction efficiency can be improved by adjusting a wavelength at which the diffraction efficiencies of a plurality of basic structures forming the optical path difference giving structure in the objective lens are maximum, in accordance with a basic structure. <P>COPYRIGHT: (C)2010,JPO&INPIT |
