| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head device which obtain a small and stable track error signal for performing recording and/or reproducing of a plurality of types of optical recording media and have high efficiency, and to provide an optical information recording and reproducing device. <P>SOLUTION: Light P<SB>D</SB>and light P<SB>C</SB>emitted from a two-wavelength light source are made incident on a diffraction optical element 3a in the same polarizing direction. Diffraction gratings 15a and 15b have birefringence and at these potions, polarizing directions of two light beams cross. The diffraction grating 15a divides light in the band of 650 nm into zero-order light and ±one-order diffracted light while the diffraction grating 15b transmits the light. The diffraction grating 15a transmits light in the band of 780 nm while the diffraction grating 15b divides the light into zero-order light and ±one-order diffracted light. The diffraction optical element 3a emits the two light beams in the same polarizing direction and the two light beams go to an optical recording medium via a polarization beam splitter and 1/4 wavelength board. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
