| 摘要 |
<P>PROBLEM TO BE SOLVED: To precisely obtain a desired signal from an optical disk having a plurality of recording layers. <P>SOLUTION: A luminous flux of P-polarized light emitted from a light source unit 51 is reflected by an optical disk 15 and becomes S-polarized light to enter a lens 61. Then, both of 1/4 wavelength plates 62 and 63 impart an optical phase difference of +1/4 wavelength to the luminous flux having entered the +X side of an optical axis, and impart an optical phase difference of -1/4 wavelength to the luminous flux having entered the -X side. Thus, signal light through the 1/4 wavelength plate 63 becomes the S-polarized light, and stray light becomes P-polarized light, so that a polarizing optical element 64 transmits only the signal light. <P>COPYRIGHT: (C)2007,JPO&INPIT |
