PURPOSE: To detect a signal by high CN ratio by using the difference of an outgoing polarized light characteristic for incident linearly polarized light between recorded/unrecorded parts due to the phase change of a crystaline substance between the crystaline substance and a non-crystaline substance.
CONSTITUTION: When an optical axis 6 makes an angle θ against the vibrating direction of the incident linearly polarized light, in an optical recording medium 1, the incident linearly polarized light advances as being separated into a linearly polarized light component inclined at the angle θ against the incident linearly polarized light and the linearly polarized light component vibrating perpendicularly to it. Phase difference is caused from the difference of a refractive index for the respective components, and after being transmitted through the medium 1, it enters an analyzer 4 as elliptic plarized light. Even if the analyzer 4 is in a cross nicol state, a part of the light is transmitted through the analyzer 4, and a light receiving element 5 outputs signal detection output, and it can be distinguished from the recording part of output '0'. In the case the optical axis 6 is parallel with or perpendicular to the vibrating direction of the incident linearly polarized light, a double refraction phenomenon is not observed, and the output is 0. Through this configuration, the signal can be detected by the high CN ratio, and recording sensitivity too can be improved by thinning a recording medium layer.
| JP4949355 | Wavelength selection switch |
| JP3298579 | POLARIZATION ILLUMINATION DEVICE |
| JPS5979220 | OPTICAL ISOLATOR USING SUPERPOSED PHASE PLATE |
IDE YUKIO
KAGEYAMA YOSHIYUKI
YAMADA KATSUYUKI
IWASAKI HIROKO
