| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element, an aberration correction element and a condensing element for optical pickup device, an objective optical system, an optical pickup device, and an optical information recording and reproducing device, which include a high-density optical disk and a DVD using a purple-blue color laser light source, and which can appropriately record and/or reproduce information to plural kinds of optical information recording media for which wavelengths to be used differ. <P>SOLUTION: This optical element for optical pickup device reproduces and/or records the information to a first and a second optical information recording medium using light beams of a first and second wavelength λ1, λ2. The optical element has an optical functional surface provided with a superposition type diffraction structure, which is such a structure that a plurality of ring-shaped zones provided with a plurality of level differences in its interior are formed concentrically around an optical axis, and an optical functional surface provided with a diffraction structure consisting of a plurality of ring-shaped zones divided with the level differences in the direction of an optical axis. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
