| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical element applicable to recording/reproducing of four types of optical recording media, having high diffraction efficiency and optical performance, and provide an optical pickup device using the same. <P>SOLUTION: The optical element 11 is provided with a first structure 11A configured by stacking a first member 11A1 made of an isotropic material and a second member 11A2 having refraction index diffeent by incident polarizing direction and disposing a first diffraction part A3 in the boundary thereof, and a second structure 11B configured by stacking a third member 11B1 made of an isotropic material and a fourth member 11B2 made of an abnormally dispersed material, and disposing a second diffraction part 11B3 in the boundary thereof. Four types of optical recording media are dealt with by disposing the optical element 11 before a single objective lens, and switching the polarizing direction of the incident light of the optical element 11. <P>COPYRIGHT: (C)2008,JPO&INPIT |
