Abstract: This invention relates to the field of materials of the photorefractive crystal. The composition of these crystals is Li1−xNb1+yO3: Fem, Mn, where M can be magnesium, indium, or zinc; when using q to denote the ion valence of M (q=2 when M is Mg or Zn, and q=3 when M is In), the values of x, y, m, and n are in the range of 0.05≦x≦0.13, 0.00≦y≦0.01, 5.0×10−5≦m≦7.5×10−4, and 0.02≦qn≦0.13. This invention greatly improves the photorefractive properties of LiNbO3 crystals: makes it have a high diffraction efficiency (more than 68%), a fast response speed for photorefraction (an order of magnitude faster than iron doped LiNbO3), and a high resistance to optical scattering (the light intensity threshold to photorefractive fan scattering near two orders of magnitude larger than LiNbO3: Fe). This invention is an excellent three-dimensional optical storage material and has a vast potential market.

Abstract: The invention relates to the information storage. It consists of a computer, a precise rotary table, a writing laser source, a readout laser source, a spatial filter, a spatial light modulator, lens, mirrors, photorefractive crystals (such as doubly doped lithium niobate), and a phase-mismatch adjustor; Due to used a green light (532 nm) as the writing light, and a red light (670 nm) as the readout light, the signal-to-noise ratio is improved greatly and the problem of fixing the stored information is solved. The transmission configuration is used to realize the high-density digital storage in which the irregular lens is designed to work as a phase-mismatch adjustor and read out the whole stored image with no distortion and loss. The dynamically differential encoding and decoding technique is used to suppress the bit-error-rate to lower than 10−6.

Abstract: The invention relates to the information storage. It consists of a computer, a precise rotary table, a writing laser source, a readout laser source, a spatial filter, a spatial light modulator, lens, mirrors, photorefractive crystals (such as doubly doped lithium niobate), and a phase-mismatch adjustor; Due to used a green light (532 nm) as the writing light, and a red light (670 mn) as the readout light, the signal-to-noise ratio is improved greatly and the problem of fixing the stored information is solved. The transmission configuration is used to realize the high-density digital storage in which the irregular lens is designed to work as a phase-mismatch adjustor and read out the whole stored image with no distortion and loss. The dynamically differential encoding and decoding technique is used to suppress the bit-error-rate to lower than 10−6.

Abstract: This invention relates to the field of materials of the photorefractive crystal. The composition of these crystals is Li1−xNb1+yO3: Fem, Mn, where M can be magnesium, indium, or zinc; when using q to denote the ion valence of M (q=2 when M is Mg or Zn, and q=3 when M is In), the values of x, y, m, and n are in the range of 0.05≦x≦0.13, 0.00≦y≦0.01, 5.0×10−5≦m≦7.5×10−4, and 0.02≦qn≦0.13. This invention greatly improves the photorefractive properties of LiNbO3 crystals: makes it have a high diffraction efficiency (more than 68%), a fast response speed for photorefraction (an order of magnitude faster than iron doped LiNbO3), and a high resistance to optical scattering (the light intensity threshold to photorefractive fan scattering near two orders of magnitude larger than LiNbO3: Fe). This invention is an excellent three-dimensional optical storage material and has a vast potential market.