| 摘要 |
PURPOSE:To record data with a high density and with a large capacity by recording the data in a thick recording material three-dimensionally one point by one point and reading it using a confocal optical system. CONSTITUTION:At a writing time, a laser beam is converged on the recording material using a LiNbO3 crystal with a large refractive index through an objective lens, and by a photorefractive effect, a change in the refractive index is generated only in the vicinity of the converged point of the laser in proportion to the differential value of the distribution of light intensity, and the data is recorded in the crystal. At this time, the data is recorded one point by one point while performing three-dimensional scan by moving the recording material in triaxial directions. At a reading time, the laser with a wavelength occurring no photorefractive effect of the LiNbO3 crystal or the laser beam with weak intensity is converged on a part generating the change of the refractive index in the recording material 5 through the objective lens 3, and the reflected beam is detected by a point detector 7 arranged on the focal position of the lens 3, and the point data is read. Thus, the data with large capacity is recorded and write/read of the data is performed. |
