| 摘要 |
<p>A volume holographic memory-based optical information-recording/reproducing apparatus is capable of controlling an interference area formed by a reference beam 5 and a signal beam 4 within a recording medium 10 more easily than by waveform shaping using a lens. A recording medium 10 is installed in the apparatus for recording a three-dimensional optical interference pattern formed by at least two coherent light beams 4, 5 as spatial changes in refractive index of the recording medium 10. A signal beam optical system 1, 3, 6, 7 transmits a coherent signal beam 4 to the recording medium 10 through a Fourier transform lens 8. A reference beam optical system 11, 12 transmits a coherent reference beam 5 to the recording medium 10. The reference beam 5 intersects the signal beam 4 within the recording medium 10, and an angle of intersection between the reference beam 5 and the signal beam 4 is changed by mirror 12. Diffracted light of the reference beam 5 diffracted from the recording medium 10 is detected by a detector 21. Light intensity distribution-offset means 51, 52, 51', 52' is arranged in the paths of the signal and reference beams 4, 5, for controlling a distribution of a light intensity of the signal beam 4 and a light intensity of the reference beam 5, respectively, within the area in the recording medium 10 in which the signal beam and the reference beam intersect with each other. <IMAGE></p> |
