| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which can effectively suppress aberration that occurs in a laser beam by lens shift or the like even though the lens shift or the like is occurred in an objective lens and in which an aberration correction element can be prevented from being made large and complicated. <P>SOLUTION: A phase correction element is used to adjust a wavefront of the laser beam. The phase correction element is provided with an electrode layer 143, an electrode layer 144 arranged oppositely from the electrode layer 143, alignment layers 145 arranged at surfaces facing the electrode layers 143 and 144, and a liquid crystal layer 146 filled between the alignment layers 145. An electrode pattern based on a mixed function between a third-order spherical aberration function and a spherical wavefront function is arranged on the electrode layer 143. At that time, an electrode based on the mixed function is not arranged but only one undivided uniform ring-shaped electrode E14 is arranged outside a beam incident diameter (that corresponds to effective diameter of an objective lens). <P>COPYRIGHT: (C)2007,JPO&INPIT |
