| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical recording and reproducing method and an apparatus for increasing the density and the capacity of an optical recording medium. SOLUTION: A waveguide medium 1a comprising one or more core layers 2, two or more clad layers 3 arranged so as to put the core layers 2 therebetween, and one or more diffraction grating layers 4 arranged at a boundary between the core layer 2 and the clad layer 3 is used. Recording information is hologram-recorded on the diffraction grating layer 4. When a reference beam 5 is made incident on the core layer 2, the reference beam is propagated through the core layer 2 as a propagated light beam 6, and the propagated light beam 6 is diffracted by the diffraction grating layer 4. The recording information recorded on the diffraction grating layer 4 is emitted as a reproduction light beam 8, and a hologram-reproduced image is formed on or in the waveguide medium 1a. A reproduction light beam 8' from the hologram-reproduced image is condensed by a collector 14, guided to a photodetector 15 by an optical system, and the light intensity of the reproduction light beam 8' is detected by a photodetector 15, thereby the recording information is reproduced. COPYRIGHT: (C)2003,JPO
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