| 摘要 |
PURPOSE:To remove optical noise from the laser emission of a light source and to stably emit a laser beam by equipping an optical head with an element to convert linearly polarized light to circularly polarized light or to convert the circularly polarized light to the linearly polarized light by means of reflection and with a polarizer. CONSTITUTION:An emitting laser beam emitted from a light source 1 is made incident on a polarizer 10, converted into the linearly polarized light, converted into the circularly polarized light by means of a reflection type optical element 9, and radiated on an information recording medium 5. A reflecting laser beam from an information recording medium 5 is reflected again by the reflection type optical element 9, and thereby, it is converted to the linearly polarized light to be rotated approximately by 90 deg. to the linearly polarized light direction of an emitting laser beam L transmitted through the polarizer 10. Consequently, the laser beam reflected and made incident on the polarizer 10 is reflected or absorbed, and the light to be fed back to the light source 1 can be almost removed. Thus, the stable emission of the laser beam can be maintained. |
