| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical pickup that can be disposed even in a small space but can make the correct output control of a laser without being influenced by the polarization change of a laser light source. <P>SOLUTION: Light from a semiconductor laser 28 enters a polarization beam splitter 34 through a birefringent plate 32, and 90% of the necessary 0th light propagates in the direction of an objective lens 46 with 10% diverted in the direction to a front monitor 36. When the polarization of the semiconductor laser 28 changes, the unnecessary primary light concentrated by the birefringent plate 32 is totally reflected by the polarization beam splitter 34 and reaches the direction of the front monitor 36. This unnecessary primary light is interrupted by a shade 38 covering the light receiving section of the front monitor 36. Thus, the unnecessary primary light does not affect the output of the front monitor 36. Since the unnecessary primary light does not affect the output of the front monitor even when a polarizing state changes, a laser output can be controlled properly. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
