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1.
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.
关键词:
气相平衡扩散
3晶体')" href="#">掺镁LiNbO3晶体
周期极化 相似文献
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我们通过测定MgO在同成分LiNbO3中的有效分凝系数、相位匹配温度与MgO浓度之间的关系,找到了使Mg:LiNbO3晶体的相位匹配温度达到最高的掺MgO配方,并克服了Mg:LiNbO3晶体在高掺杂生长时易出现生长条纹和脱溶等问题,从而生长出了抗光折变能力强,光学均匀性良好的Mg:LiNbO3晶体。用于连续泵浦Nd:YAG声-光调Q腔内倍频时,获得了平均功率最高达2瓦的二次谐波输出。
关键词: 相似文献
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本文用X射线衍射、热处理及差热分析等方法测定了SrNb2O6-NaNbO3-LiNbO3赝三元系的室温截面及相应的SrNb2O6-NaNbO3,SrNb2O6-LiNbO3和NaNbO3-LiNbO3等三个赝二元系相图;粗略地研究了Sr0.42Na0.16NbO3-LiNbO3系的纵截面;含5mol%LiNbO3及10mol%LiNbO3的SrNb2O6-NaNbO3的纵截面。确定了室温Sr2Na(NbO3)5(以下略为S2N)相为四方钨青铜结构。其点阵常数为a=12.36?,c=3.906?.LiNbO3在S2N相内的溶解度可达~10mol%,当LiNbO3含量超过5mol%时,S2N相畸变为S2N′相。S2N′相为正交晶系。实验确定室温S2N(S2N′)相系亚稳相。在900-1100℃长时间退火即分解为SrNb2O6和以NaNbO3为基的固溶体的混合物。
关键词: 相似文献
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对LiNbO3: Fe晶体中二波耦合过程进行了动态观测.进一步探讨了LiNbO 3:Fe晶 体中弱光放大的物理机理.发现LiNbO3 : Fe晶体中二波耦合过程的弱光放大 对c轴指 向有明显的依赖关系,虽然光生伏打效应对光生载流子的迁移有主要贡献,但扩散机理的贡 献仍不可忽略.弱光最终得到放大是瞬态能量转移与扩散机理引起的能量转移的共同贡献.弱 光放大达到准稳态之后的下降过程为瞬态能量转移的时间指数衰减过程与光散射引起的能量 耗散的共同贡献.
关键词:
光折变效应
光放大
掺杂铌酸锂 相似文献
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采用外加电场法制备了LiNbO3单晶周期畴结构. 在对不同尺寸周期畴的反转电流进行比较研究的基础上,提出了一种确定反转畴成核时间和纵向贯穿速率的方法. 根据这一方法,得到在电场强度为25.1kV/mm,脉冲宽度为50 ms的脉冲方波作用下,LiNbO3单晶反转畴的成核时间约为80ns,纵向贯穿速率约为0.1667m/s.
关键词:
3单晶周期极化')" href="#">LiNbO3单晶周期极化
反转电流
反转畴成核时间
反转畴纵向贯穿速率 相似文献
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用气相输运平衡技术成功地制备出了近化学计量组分的Er∶LiNbO3晶体,系统 地研究了该 晶体的吸收边移动、可见—红外透射谱、荧光光谱的物理特性.与同成分Er∶LiNbO3 sub>晶体 相比, 近化学计量组分Er∶LiNbO3晶体的吸收边出现了“蓝移”;OH- sup>吸收带明显减弱 ;在可见—近红外波段呈现出更高的透过率;同时Er3+离子的发光强度也明显 提高. 这些结果表明近化学组分的Er∶LiNbO关键词:
近化学组分掺铒铌酸锂晶体
- 吸收带')" href="#">OH-吸收带
透射谱
荧光光谱 相似文献
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Holographic measurements in LiNbO3: Ti waveguides are reported indicating a mode dependent enhancement of photoconductivity. This enhancement can be explained by a stabilization of Fe2+ centers in the waveguide which are responsible for optical damage effects. 相似文献
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采用m线法研究了掺杂LiNbO3晶体波导基片的光损伤,发现抗光损伤能力依次为Mg:LiNbO3、LiNbO3、Fe:LiNbO3(氧化),Fe:LiNbO3(还原).对于同样材料,质子交换光波导的抗光损伤能力高于钛扩散光波导。 相似文献
13.
ShiLing Li 《中国科学G辑(英文版)》2008,51(10):1479-1488
The formation of optical planar waveguides in LiNbO3 and stoichiometric LiNbO3 crystals by proton exchange was reported. The prism-coupling method was used to characterize the dark-line spectroscopy at
the wavelength of 633 and 1539 nm, respectively. The mode optical near-field outputs from proton-exchanged LiNbO3 and SLN waveguides at 633 nm were presented. The mode field from stoichiometric LiNbO3 (SLN) waveguide is lighter and more uniform than that from LiNbO3 waveguide, which means the quality of the waveguide in SLN crystal is better than that of the LiNbO3 waveguide. For proton-exchanged LiNbO3 waveguides, the evolution of the refractive index profile with annealing was presented. The disorder profiles of Nb atoms
in proton-exchanged LiNbO3 waveguides were obtained by Rutherford backscattering/channeling technique. It is shown that the longer the exchange time,
the larger the displacement of Nb atoms.
Supported by the National Natural Science Foundation of China (Grant No. 10475052) and the Scientific Research Start-up Financing
of Qufu Normal University 相似文献
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Ti扩散Er3+:LiNbO3沟道波导的模式分析 总被引:1,自引:0,他引:1
本文采用有效折射率方法对Ti扩散Er3+:LiNbO3沟道波导的模式特性进行了分析,分析中考虑了Er3+:LiNbO3晶体的各向异性,并与变分法分析进行了比较,二者结果相一致。 相似文献
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R. Göring Zhan Yuan-Ling St. Steinberg 《Applied Physics A: Materials Science & Processing》1992,55(1):97-100
The photoconductivity and photovoltaic currents of pure LiNbO3 and proton exchanged waveguides in LiNbO3 have been measured as a function of the optical intensity up to about several kW/cm2 by the use of surface electrodes. For pure LiNbO3 the observed dependences are a simple extrapolation of the well known low intensity behaviour. The photoconductivity of proton exchanged waveguides is considerably increased compared with pure LiNbO3 and the curves are strongly nonlinear in the high intensity region. These results can explain, at least qualitatively, the previously observed characteristic time and intensity dependence of light-induced refractive index changes in this type of waveguides. Both the time and temperature behaviour of the dark conductivity of all proton exchanged waveguides give strong evidence of ionic charge transport in the proton exchanged region. 相似文献
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L. S. Kokhanchik M. V. Borodin S. M. Shandarov N. I. Burimov V. V. Shcherbina T. R. Volk 《Physics of the Solid State》2010,52(8):1722-1730
Regular domain structures on the Y cuts of the LiNbO3 substrates and Ti:LiNbO3 waveguide structures based on these substrates have been fabricated under electron-beam irradiation. It has been revealed
that the domains in undoped and titanium-doped LiNbO3 crystals are formed as a result of different processes. It has been demonstrated using chemical etching and waveguide second-harmonic
generation that regular domain structures in the Ti:LiNbO3 waveguides are formed at a depth of approximately 8 μm from the surface, where the titanium concentration does not exceed
2 mol %. The quasi-synchronous waveguide optical second harmonic generation with an efficiency of 8.8% has been obtained using
the fabricated structures. 相似文献
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A.A. Ilyich S.M. Kikkarin D.V. Petrov A.V. Tsarev I.B. Yakovkin 《Optics Communications》1985,56(3):161-166
A comparison of acoustooptic efficiency in both Ti:LiNbO3 and GaAlAs waveguides is made with the help of known results and additional experiments. It is shown that the acoustooptic figure of merit for the frequency of 100 MHz in a GaAlAs waveguide is one order of magnitude higher than in Ti:LiNbO3 waveguide. 相似文献
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The optical storage properties of LiTaO3:Fe are investigated and compared with those of the isomorphous compound LiNbO3:Fe. Absorption, photocurrent, photoconductivity and holographic measurements are reported. In the case of photovoltaic writing
similar results for LiTaO3- and LiNbO3-crystals are obtained. However, in the case of photoconductive writing using external electric fields LiTaO3:Fe-crystals yield much better results due to large photoconductivity values. Considering the recording sensitivity and the
extremely large storage time LiTaO3:Fe turns out to be one of the most promising materials for photorefractive storage of volume phase holograms. 相似文献
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I. S. Azanova D. I. Shevtsov I. F. Taĭsin A. B. Volyntsev 《Physics of the Solid State》2006,48(6):1053-1055
The parameters of proton-exchange waveguide H: LiNbO3 layers and doubly doped H: Ti: LiNbO3 layers were comparatively analyzed by x-ray diffractometry and optical mode spectroscopy. It was established that the change in the lattice parameter in hybrid H: Ti: LiNbO3 layers is significantly smaller than that in proton-exchange H: LiNbO3 layers formed under the same proton exchange conditions. The behavior of the optical and structural parameters of H: Ti: LiNbO3 layers was studied in a wide hydrogen concentration range. 相似文献
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White light interferometer can be used to measure the amplitude extinction ratio (ER) of polarizer and coupling distribution in fiber. A LiNbO3 polarizer coupled with a polarization maintaining fiber and a silica planar waveguide at the two ends was measured using white light interferometer. According to the principles of optical coherence domain polarimeter (OCDP) technique, the test scheme is analyzed and presented to measure the ER of LiNbO3 polarizer with its apparatus proposed correspondingly. By analyzing the interference intensity, both the ER of LiNbO3 polarizer and its coupling crosstalk with optical fiber and waveguide are obtained. The results illustrate that the ER of a 5 mm-long LiNbO3 polarizer is 71 dB and the crosstalk of the coupling points are around 40 dB. The results have good agreement with analysis. 相似文献