| 摘要 |
<p>An optical head includes a reflection type grating lens for dividing specified polarized lights into a reflected light and a diffracted light, a device for detecting a RF signal from the reflected light of the grating lens, and a device for detecting focusing and tracking error signals from the diffracted light of the grating lens. The grating lens (23) consists of a plurality of domains having different optical properties respectively, so that the reflected and diffracted lights are obtained. The optical head further includes a total reflection prism (6) to compensate a phase difference between polarized lights orthogonal to a grating groove of the grating lens and parallel thereto, and a polarizing prism (24) for dividing the reflected light into two polarized lights orthogonal to each other in polarization thereof. Thus, a simple, miniaturized, and inexpensive optical head is obtained.</p> |
