| 摘要 |
PROBLEM TO BE SOLVED: To attain high density recording by splitting a beam from a laser light source into two beams, making the polarizing stated of one side orthogonal through a 1/2 wavelength plate, multiplexing them again by keeping the tilt angle between the two beams. SOLUTION: The reflection light from a disk 11 of a first converged beam 112 and a second converged beam 113 become circular polarization of right rotation and left rotation, and transmit through an objective lens 110, and become collimate beams again, and are converted to linear polarization orthogonal intersecting with each other by a 1/4 wavelength. These linear polarizations become linear polarizations orthogonally intersecting with incident light on the disk 11. The reflection light of the first converged beam 112 goes straight on to a beam splitter 104, and reflects by 90 deg. at the time, and is received by a photosensor 115a, and an output A is obtained. The second converged beam is received by a quadripartite photosensor 117 through a cylindrical lens 116, and an RF signal B, a focus error signal and a tracking error signal are obtained. |
