| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a laminated wave plate that functions as a quarter wave plate at wavelengths of 400 nm, 650 nm and 780 nm necessary for an optical pickup coping with optical disks of CD, DVD and a blue laser disc as well. <P>SOLUTION: The laminated wave plate 1 is produced by stacking a wave plate 2 having 1,980° phase difference and 15° in-plane azimuth angle at 650 nm wavelength and a wave plate 3 having 990° phase difference and 75° in-plane azimuth angle, with the optical axes of the plates intersecting at an angle of 60°, and the laminated wave plate as a whole functions as a quarter wave plate at wavelengths of 400 nm, 650 nm and 785 nm. The laminated wave plate is characterized in that it functions in a pinpoint way as a quarter wave plate at wavelengths of 400 nm, 650 nm and 785 nm in a range to be used. When linearly polarized light is made incident on the laminated wave plate 1, the light exits as circularly polarized light as the phase shifts by 90° at the exit face of the laminated wave plate 1. <P>COPYRIGHT: (C)2007,JPO&INPIT |
