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以基于准位相匹配和频与差频级联二阶非线性[X^(2):X^(2)]基础上的全光开关的理论分析作指导,进行了周期极化铌酸锂晶体(PPLN)和退火质子交换光波导(APE)的实验制备,利用所研制的PPLN-APE器件,以自行研制的工作波长为1.54μm的被动调Q掺钴铝酸镁激光器作为控制光源,以工作波长为1.5μm的连续二极管激光器为信号光源进行了级联二阶非线性全光开关实验。当控制光峰值功率为3kw,信号光功率为1mW时,实现13%的开关效率,分析了进一步提高全光开关性能的途径。 相似文献
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近化学计量比掺镁铌酸锂晶体的抗光折变性能 总被引:3,自引:0,他引:3
应用气相传输平衡技术,我们获得了3种近化学计量比掺镁铌酸锂晶体,晶体的掺镁量接近我们以前提出的第二阈值.在我们实验室所能达到的最大光强26 MW/cm2照射下,在所有近化学计量比掺镁铌酸锂晶片中没有观察到光斑畸变,该光强比同成分铌酸锂晶体所能承受的光强高6个量级,为目前已报道的铌酸锂晶体之最.应用双光束全息写入法测得掺1.0 mol; Mg近化学计量比铌酸锂晶体的光折变饱和值仅有4.6×10-7,比同成分铌酸锂晶体小两个量级,从已有实验数据推测,该晶体的抗光折变能力应当比同成分铌酸锂晶体高9个量级以上. 相似文献
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Forward degenerate four-wave mixing (DFWM) processes are investigated with a femtosecond pulsed laser in lithium niobate crystal doubly-doped with magnesium and iron (LiNbO3:Fe, Mg). The pulse energy dependence reveals a pure third-order nonlinear response, and the third-order nonlinear susceptibility x^(3) in the material is evaluated to be 4.96 × 10^-13 esu. The time-resolved DFWM process shows a response time of x^(3) shorter than 100fs, which is due to the nonresonant electronic nonlinearities. Our results indicate that LiNbO3 crystals have potentials for ultrafast real-time optical processing systems, which require a large and fast x^(3) optical nonlinearity. 相似文献
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研究系数密集间断的边值问题,采用降维方法,使得在数值计算上可实现并行计算,并且收敛性的证明变得很简洁. 相似文献
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Nonvolatile two-color holographic recording gated by incoherent ultraviolet (UV) light centered at 365 nm is investigated in near-stoichiometric lithium niobate crystals. The influence of thermal treatment on the two-color recording is studied. The results show that thermal reduction tends to improve the two-color recording performance, whereas thermal oxidation degrades the two-color recording. With an incoherent 0.2-W/cm2 UV gating light and a 0.25-W/cm2 semiconductor recording laser at 780 nm, a two-color recording sensitivity of 4 × 10^-3 cm/J and a recording dynamic range characterized by M/# of 0.12 are achieved in a 2.2-mm thermally reduced near-stoichiometric lithium niobate crystal. We attribute the improvement to the prolonged lifetime of small polarons and the increased absorption at the gating wavelength due to thermal reduction. 相似文献
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近化学计量比LiNbO3晶体的生长及其组分测定 总被引:9,自引:5,他引:4
铌酸锂晶体(LiNbO3)是一种典型的非化学计量比晶体,通常所使用的同成分LiNbO3晶体中的锂铌比([Li]/[Nb])约为48.6/51.4。我们利用提拉法,从掺入11mol%K2O的同成分LiNbO3熔体中生长出了高光学质量的近化学计量比LiNbO3单晶。与同成分LiNbO3晶体相比,其吸收边向短波方向移动;E模(153cm^-1)喇曼谱线宽从9.4cm^-1降低到了7.0cm^-1,A1模(876cm^-1)喇曼谱线宽从25.5cm^-1降低到了20.0cm^-1;产生532nm-1064nm2次谐波的相匹配温度从室温增加到了155.5℃;OH^-红外吸收谱线宽明显变窄,波形也有明显的变化。这些结果表明这种LiNbO3晶体中的LiO2含量为49.6mol%, 即[Li]/[Nb]为0.984,接近其化学计量比。 相似文献
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利用气相平衡扩散法研制出掺镁不同组分的LiNbO3晶体 ,并对其极化特性进行了研究 .研究表明晶体的开关电场和自发极化不仅与晶体组分 [Li] [Nb]比有关而且与掺镁量有关 ,[Li] [Nb]比为 0 973掺入 2mol%MgO的近化学比LiNbO3晶体的开关电场仅为 1 8kV mm ,是同成分晶体的 1 12 ,且其极化结构的质量要远好于同成分LiNbO3晶体和近化学比LiNbO3晶体 . 相似文献
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We detect the photo-induced carriers in near-stoichiometric iron doped LiNbO3 crystal by the holographic technique. The results show that the dominant carriers are electrons in the sample with Li/Nb ratio of 0.9988. By analysis of the OH^- absorption spectra of the crystal, we contribute the electron domination in near-stoichiometric Fe-doped LiNbO3 crystal to the existence of NbLi which provides the anti-site defect to Fe^2+. 相似文献