| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical device having quarter wavelength plate function, numerical aperture limiting function and wavefront aberration correction function in order to manufacture with good productivity a compact optical head having high light utilization efficiency compatible with both CD and DVD by use of a single objective lens. <P>SOLUTION: The integrated optical device includes a numerical aperture limiting element 11 having a central portion transmitting two-wavelength light and a peripheral portion surrounding the central portion and reflecting or diffracting one of the light, and a wavefront aberration correction element 14 having an annular groove to correct the wavefront, which are secured with an adhesive agent 13 from the both sides via a birefringent organic thin film 12. <P>COPYRIGHT: (C)2009,JPO&INPIT |
