| 摘要 |
PROBLEM TO BE SOLVED: To provide an inexpensive separating element for polarized light and an optical pickup and to provide a production method of the optical separating element for polarized light without using an optically isotropic substrate such as lithium niobate and titanium oxide. SOLUTION: The separating element 10 for polarized light 10 consists of an optical glass substrate 11 and a polydiacetylene oriented film 12a as a double refraction material layer 12. The polydiacetylene oriented film 12a is irradiated with UV rays in a specified pattern to form a periodical grating 12b comprising a part 121 where the hue is changed and a part 122 where the hue is not changed. Therefore, the refractive index periodically changes between high and low in the orienting direction of the polydiacetylene oriented film 12a, while the refractive index hardly changes in the direction perpendicular to that. Thereby, the polarized light in the orienting direction is diffracted while the polarized light perpendicular to that transmits. The obtd. separating element 10 for polarized light can be used as an optical device of an optical pickup. |
