| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain an optical head device for stably detecting a signal by obtaining an optical element for converting a linear polarized light with two type wavelengths having parallel polarized planes into orthogonally polarized planes. <P>SOLUTION: An organic thin films 14 having birefringence is laminated in two transparent substrates 11 and 16 via adhesive 15. A phase element 101 constructed such that the organic thin film 14 gives a phase difference of 2π(m<SB>1</SB>-1/2) to the polarized light with the one wavelength and phase difference of 2πm<SB>2</SB>to the other polarized light is mounted on the optical head device. The optical axes of two irradiated lights coincides with each other and then each optical component in the optical head device exerts good optical characteristics so that stable signal detection could be achieved with least reading error when reproducing the information on an optical disk and least writing error when writing information on the optical disk. <P>COPYRIGHT: (C)2011,JPO&INPIT |
