| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarization separation element having a function to determine the optical path to detect the tilt of an optical recording medium, and a method for manufacturing the same. SOLUTION: The polarization separation element 10 has polarizing gratings 17, 18 produced by forming a periodical rugged structure on the surface of an organic birefringent film 13 formed on an optically isotropic substrate 11 and then filling the recesses of the periodical structure with an overcoat layer 15, and has a non-polarizing grating having a periodical rugged structure formed as integrated with the entrance face 10A for laser light of the optically isotropic substrate 11. The non-polarizing grating is smaller in size than the region (size) of the sum of the polarizing diffraction gratings 17, 18 and is formed to give an optical path between the non-polarizing grating and the polarizing grating 18. |
