| 摘要 |
PURPOSE:To reduce the optical loss without using any half mirror, etc. by setting the reflection factor of a polarized beam splitter so that the luminous flux on a polarizing surface is totally transmitted or reflected to the side of an objective lens in an insident mode. CONSTITUTION:The light beam delivered from a polarized beam splitter 3 is condensed by an objective lens 5 via a 1/4 wavelength plate 4 and then irradiated to an optical disk 7 which is revolved by a spindle motor 6. Then the light beam is reflected on the disk 7 and made incident to the splitter 3 in the adverse direction. The greater part of the incident light is reflected rectangularly and reaches a detector 8. In such a constitution, no optical loss is produced on a going path without using any half mirror, etc. Thus it is possible to lead the laser light effectively to the disk surface. |
