| 摘要 |
PURPOSE:To attain miniaturization and simultaneously to improve efficiency in optical utilization by using the combination of a reflection type beam shaping prism and grating. CONSTITUTION:A beam of light emitted from a semiconductor laser 1 is deflected at right angle by being reflected by the reflection area 12a of the reflection type beam shaping prism 12; after being shaped with a desired beam shaping ratio, it irradiates the face of an magneto-optical disk 5, and the recording of information, etc., is performed. Also, the reflected light from the disk 5 is made incident on the prism 12, and by transmitting through a grating face 13a of a grating element 13, is divided into a deflected transmitted light T and a diffracted light K which are orthogonally crossed with each other. These transmitted light T and diffracted light K are reflected by a total reflection face 13b; the transmitted light T further passes through transmissively, the diffracted light K is further diffracted, and respectively received by a light receiving element 6. In this case, focus error signals and track error signals are respectively detected. |
