In this paper, photorefractive crystals of Ce, Fe:LiNbO 3 are systematically studied. The crystals have been grown by Czochralski method. The samples with different doping concentrations and oxidation/reduction treat...In this paper, photorefractive crystals of Ce, Fe:LiNbO 3 are systematically studied. The crystals have been grown by Czochralski method. The samples with different doping concentrations and oxidation/reduction treatments have been fabricated. Their photorefractive properties were experimentally investigated by using two beam coupling. The results show that the photorefractive efficiency depends on the dopant concentration, oxidation/reduction treatment, and light wavelength. The doping mechanism is also discussed here.展开更多
By jointly solving two-centre material equations with a nonzero external electric field and coupled-wave equations, we have numerically studied the dependence of the non-volatile holographic recording in LiNbO3：Ce：C...By jointly solving two-centre material equations with a nonzero external electric field and coupled-wave equations, we have numerically studied the dependence of the non-volatile holographic recording in LiNbO3：Ce：Cu crystals on the external electric field. The dominative photovoltaic effect of the non-volatile holographic recording in doubly doped LiNbO3 crystals is directly verified. And an external electric field that is applied in the positive direction along the c-axis （or a large one in the negative direction of the c-axis） in the recording phase and another one that is applied in the negative direction of the c-axis in the fixing phase are both proved to benefit strong photorefractive performances. Experimental verifications are given with a small electric field applied externally.展开更多
Fe（0.2 mol%）：Cu（0.04 mol%）：LiNbO3 crystals with different doping concentration of In^3＋ （0, 1.0, 2.0, 3.0mol%） were grown by Czochralski method, and then oxidized and reduced. The infrared transmittance spect...Fe（0.2 mol%）：Cu（0.04 mol%）：LiNbO3 crystals with different doping concentration of In^3＋ （0, 1.0, 2.0, 3.0mol%） were grown by Czochralski method, and then oxidized and reduced. The infrared transmittance spectra of crystals were measured to investigate the location of doping ion and its threshold concentration. The photorefractive properties of the crystals were tested by two beam coupling experiment. The results showed that the threshold concentration of In ions is 2.0～ 3.0 mol% and In ions take the place of NbLi^4＋ to form （ InLi^2＋） before reaching its threshold concentration, and then the location of normal Nb ions. In the （2.0 mol%）：Fe：Cu：LiNbO3 crystal with the oxidation treatment having the highest diffraction efficiency （η = 45.8%）, the photo-damage resistance threshold value R of In（3.0 mol%）：Fe：Cu：LiNbO3 was 3.67×10^4 W/cm^2 which was two orders of magnitude higher than that of Fe：Cu：LiNbO3 crystal （4.30×10^2 W/cm^2）. And the photo-damage resistance ability was enhanced by oxidized treatment. The In（2.0～3.0 mol%）：Fe：Cu：LiNbO3 crystals with oxidized treatment have the best photorefractive properties.展开更多
Nonvolatile holographic recording is performed with green light in LiNbO3：Ce：Cu crystals. The refractiveindex change and the recording sensitivity are times better than those obtained by recording with red light, an...Nonvolatile holographic recording is performed with green light in LiNbO3：Ce：Cu crystals. The refractiveindex change and the recording sensitivity are times better than those obtained by recording with red light, and higher optical fixing efficiency is obtained. Correspondingly, theoretical investigations are given.展开更多
The bleaching effect, i.e. the crystal shows that decoloration after it is illuminated by ultraviolet light, has been observed in congruent LiNbO3:Fe:Cu crystals. Based on this bleaching effect, a new technique includ...The bleaching effect, i.e. the crystal shows that decoloration after it is illuminated by ultraviolet light, has been observed in congruent LiNbO3:Fe:Cu crystals. Based on this bleaching effect, a new technique including the recording phase by two interfering red beams and fixing phase by both UV light and a coherent red beam has been experimentally investigated to realize nonvolatile holographic storage in LiNbO3:Fe:Cu. The results of proof-of-concept experiments confirm that bleaching effect becomes an alternative physical mechanism for nonvolatile holographic storage with high recording sensitivity and weak light-induced scattering noise.展开更多
文摘In this paper, photorefractive crystals of Ce, Fe:LiNbO 3 are systematically studied. The crystals have been grown by Czochralski method. The samples with different doping concentrations and oxidation/reduction treatments have been fabricated. Their photorefractive properties were experimentally investigated by using two beam coupling. The results show that the photorefractive efficiency depends on the dopant concentration, oxidation/reduction treatment, and light wavelength. The doping mechanism is also discussed here.
基金Project supported by the State Science and Technology Commission of China （Grant No 2002CCA03500） and the National Natural Science Foundation of China （Grant No 60177016）.
文摘By jointly solving two-centre material equations with a nonzero external electric field and coupled-wave equations, we have numerically studied the dependence of the non-volatile holographic recording in LiNbO3：Ce：Cu crystals on the external electric field. The dominative photovoltaic effect of the non-volatile holographic recording in doubly doped LiNbO3 crystals is directly verified. And an external electric field that is applied in the positive direction along the c-axis （or a large one in the negative direction of the c-axis） in the recording phase and another one that is applied in the negative direction of the c-axis in the fixing phase are both proved to benefit strong photorefractive performances. Experimental verifications are given with a small electric field applied externally.
基金This work was supported by Harbin Science and Technology Project (No. 2005AA5CG058)Natural Science Foundation of Heilongjiang Province (No. A0203)
文摘Fe（0.2 mol%）：Cu（0.04 mol%）：LiNbO3 crystals with different doping concentration of In^3＋ （0, 1.0, 2.0, 3.0mol%） were grown by Czochralski method, and then oxidized and reduced. The infrared transmittance spectra of crystals were measured to investigate the location of doping ion and its threshold concentration. The photorefractive properties of the crystals were tested by two beam coupling experiment. The results showed that the threshold concentration of In ions is 2.0～ 3.0 mol% and In ions take the place of NbLi^4＋ to form （ InLi^2＋） before reaching its threshold concentration, and then the location of normal Nb ions. In the （2.0 mol%）：Fe：Cu：LiNbO3 crystal with the oxidation treatment having the highest diffraction efficiency （η = 45.8%）, the photo-damage resistance threshold value R of In（3.0 mol%）：Fe：Cu：LiNbO3 was 3.67×10^4 W/cm^2 which was two orders of magnitude higher than that of Fe：Cu：LiNbO3 crystal （4.30×10^2 W/cm^2）. And the photo-damage resistance ability was enhanced by oxidized treatment. The In（2.0～3.0 mol%）：Fe：Cu：LiNbO3 crystals with oxidized treatment have the best photorefractive properties.
基金This work was supported by the Science and Tech-nology Committee of China (No. 2002CCA03500) the National Natural Science Foundation of China (No.60177016).
文摘Nonvolatile holographic recording is performed with green light in LiNbO3：Ce：Cu crystals. The refractiveindex change and the recording sensitivity are times better than those obtained by recording with red light, and higher optical fixing efficiency is obtained. Correspondingly, theoretical investigations are given.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 60177016)the Science Committee of Shanghai (Grant No. 012261011)the National Outstanding Youth Foundation of China (Grant No. 60125512).
文摘The bleaching effect, i.e. the crystal shows that decoloration after it is illuminated by ultraviolet light, has been observed in congruent LiNbO3:Fe:Cu crystals. Based on this bleaching effect, a new technique including the recording phase by two interfering red beams and fixing phase by both UV light and a coherent red beam has been experimentally investigated to realize nonvolatile holographic storage in LiNbO3:Fe:Cu. The results of proof-of-concept experiments confirm that bleaching effect becomes an alternative physical mechanism for nonvolatile holographic storage with high recording sensitivity and weak light-induced scattering noise.
