| 摘要 |
<P>PROBLEM TO BE SOLVED: To efficiently extract signal light from luminous flux containing signal light and stray light. <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 polarization beam splitter 53. Then, return light branched in a -Z direction by the polarization beam splitter 53 becomes convergent light by a condensing lens 57, and enters a polarization longitudinal slit 58. The polarization longitudinal slit 58 converts signal light included in the return light to P polarization, and the stray light is reflected toward the condensing lens 57 while keeping S polarization. The return light that becomes parallel light by the condensing lens 57 after being reflected by the polarization longitudinal slit 58 enters an extraction element 56, and only P polarization is reflected toward a photo detector 59. <P>COPYRIGHT: (C)2009,JPO&INPIT |
