| 摘要 |
PURPOSE:To improve the S/N of a reproduction signal by using a total reflection prism, a beam splitter, etc. to correct the phase difference between the incident linear polarization component of the reflected light sent from a photomagnetic recording medium and the polarization component orthogonal to said linear polarization component. CONSTITUTION:The light delivered from a semiconductor laser 11 is turned into parallel beams by the linear polarization parallel to the paper surface and through a collimator lens 12 and formed into an approximately circular intensity distribution by a shaping prism 13. The these beams are made incident on a beam splitter 14 with P polarization and the beams transmitted through the splitter 14 are made incident on a total reflec tion prism 15 with S polarization. Here a phase difference occurs by the reflection of the prism 15. However the light incident on the prism 15 contains just the P polariza tion and no P polarization component and is never formed into an oval. The light formed into an oval by the reflection through a recording medium 23 is reflected again by the prism 15 to undergo the linear polarization. This linear polarized light is reflected by a beam splitter 16 and transmitted through a photodetector 19. Then a signal is detected by a light detector 21. Thus the S/N of a reproduction signal is improved.
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