| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive optical element for an optical pickup having high performance by utilizing a birefringent structure by molding of a resin. <P>SOLUTION: In a 1/4 retardation plate 4 for the optical pickup constituted by structural birefringence composed of a diffraction grating having submicron pitches, a grating pattern 41 having the submicron pitches of a double periodic structure is disposed integrally on the surface of a substrate 40, a thin film 42 having high refractive index is provided on the surface of the grating pattern 41 and the grating pattern 41 provided on the substrate 40 and the thin film 42 thereon constitute the structural birefringence. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
