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对6个点光源进行光学傅里叶变换,在自散焦光折变掺铁铌酸锂晶体中成功制作了具有100余条椭圆柱阵列波导。研究表明,这些阵列波导构成了大带隙的椭圆柱光子晶体。测得沿着椭圆长轴、短轴方向的晶格常数分别26um和15um。 相似文献
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《高校化学工程学报》2004,18(5):670-670
论文题目(带*者为博士论文) Topics of Thesis(*Ph. D. Dissertation) 日期 Date 学生姓名 Student 导师姓名 Advisor 哈尔滨工业大学 Harbin University of Technology 稀土铬酵母的制备与应用研究 2003.7 史瑞欣 金 婵 ZnS:Cu发光粉的包膜处理研究 2003.7 贾瑞宝 王 锐 铟锌铌酸锂和铟锌铌酸锂晶体的制备及光学性能研究 2003.7 聂义然 王 锐 SOFC用镓酸镧基固体电解质的制备及其性能研究 2003.7 吴宁宁 孙克宁 纳米Ni(OH)混合镍电极电化学机理及导电剂性能研究 2003.7 谢小美 韩喜江 Pr对PdTiO3陶瓷的气相扩渗及其电性能 … 相似文献
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对4个点光源进行光学傅里叶变换,在自散焦光折变掺铁铌酸锂晶体中成功制作了具有300余条波导的光子晶体,并实验证明了该光子晶体具有导向较长波长光的性质。随后利用理论模型制作了具有不同周期的2种四方形光子晶体。 相似文献
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铌酸锂晶体中存在着丰富的缺陷结构,主要包括VLi、NbLi4+、VNb以及VO等点缺陷。缺陷的存在会在很大程度上影响铌酸锂晶体的性质,如压电、电光、铁电、光折变、非线性光学性质以及激光损伤阈值,进而影响声表面波、电光调制器、声光调制器、温度/压力/加速度传感器等器件性能。铌酸锂晶体中缺陷形成的主要过程可以归结为以O2–为中心的介尺度团簇演变。明确铌酸锂晶体缺陷形成过程中的介尺度团簇演变机制对于缺陷的控制具有十分重要的意义。本文将从缺陷类型、形成能以及介尺度团簇模型研究铌酸锂晶体中缺陷的动态演变过程以及形成机制。最后分析铌酸锂晶体结构中缺陷导致的杂化、再杂化过程,同时考虑多种自由度的耦合,为铌酸锂晶体的缺陷控制、快速生长以及性能调控贡献力量。最后举例介绍分析铌酸锂晶体缺陷与性质、功能的关联关系。 相似文献
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采用无籽固相晶体生长法制备了铌酸钾钠基压电单晶,研究了晶体生长降温阶段的冷却速率对该单晶的结构和性能的影响。结果表明:通过优化降温速率有利于单晶的生长,易生长尺寸更大的单晶体;当降温速率较低时,晶体表面更平坦,晶体质量较高;在研究范围内,降温速率的改变对单晶的晶体结构的影响较小;当降温速率为2.0℃/min时,所制备的铌酸钾钠基压电单晶表现出优异的压电性能,其正压电系数d33达510 pC/N,逆压电系数d*33达1 425 pm/V,同时晶体还具有较低的介电损耗tanδ=0.02,且Curie温度较高TC=416℃,和剩余极化强度Pr=20μC/cm2。通过优化降温速率采用无籽固相法生长的铌酸钾钠基单晶是一种较有前景的压电铁电单晶材料,具有较大的潜在应用价值。 相似文献
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首次测量了同成分和掺铁铌酸锂晶体中氧空位的生成焓,发现掺铁可以使铌酸锂晶体中氧空位生成焓大为降低。讨论了实验结果,并提出光折变铌酸锂晶体的还原处理可以在较低的温度下进行。 相似文献
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Noor Farahin Mohd Ibrahim Mohamad Riduwan Ramli Arjulizan Rusli Mohd Kamil Abd Rahman Zulkifli Ahmad 《应用聚合物科学杂志》2020,137(47):49554
Optical properties of two-fluorinated polysiloxane-co-polyimide (PI-PDMS and 3-(aminopropyl)triethoxysilane [PI-APTES]) were investigated based on their molecular structure and compared with the pure PI at 1,550 nm radiation. The refractive indexes and birefringence of the copolymers were reduced which is attributable to the chain flexibility as substantiated from the differential scanning calorimetry result. They are highly transparent at near infrared (NIR) region with light transmittance above 90% at visible region while displaying excellent thermal stability up to 456°C. Asymmetry planar waveguides was fabricated which recorded a respectable low optical loss 0.020 dB/cm for pure PI, 0.042 dB/cm for PI-PDMS, and 0.066 dB/cm for PI-APTES, respectively. Despite proving low NIR absorption and low birefringence, extrinsic factor namely surface roughness was accounted as affecting the higher optical loss in polyimide siloxane copolymer compared to pure PI. The excellent thermal and optical properties displayed by these series of material established their viable application as waveguide material at 1,550 nm wavelength. 相似文献
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采用提拉法生长了不同Sc掺杂的Sc:Mn:Fe:LiNbO3晶体,通过紫外-可见光谱测试分析了Sc:Mn:Fe:LiNbO3晶体的缺陷结构,利用光斑畸变法表征了其抗光损伤能力.结果表明:当Sc2O3的浓度超过阈值浓度(1.5%,摩尔分数)时,Sc:Mn:Fe:LiNbO3晶体的抗光损伤能力远远高于未达到阈值浓度的晶体,其紫外-可见光谱将发生红移;当Sc2O3的浓度未达到阈值浓度时,随着Sc掺量的增加,Sc:Mn:Fe:LiNbO3晶体的紫外-可见光谱将发生紫移. 相似文献
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在LiNbO3(LN)中分别掺入0.5%(摩尔分数,下同),1%和2% MgO,0.03%(质量分数)Fe2O3,配料中n(Li)/n(Nb)=1.38,采用顶部籽晶溶液生长法生长近化学计量比Fe:Mg:LiNbO3(near-stoichiometric Fe:Mg:LiNbO3,Fe:Mg:SLN)晶体。测试了晶体的红外光谱、抗光损伤能力和存储性能。结果表明:Fe:2%Mg:LN晶体的OH-吸收峰移到3535cm-1,抗光损伤能力比Fe:LN提高3个数量级。Fe:0.5%Mg:LN晶体的灵敏度、动态范围和抗光损伤能力比Fe:LN晶体分别高2.5倍,2倍和1个数量级。以Fe:2%Mg:LN晶体和Fe:LN晶体分别作为存储介质,进行大容量存储实验。在一个公共体积内实现1200幅体全息图的存储。Fe:2%Mg:LN晶体的存储质量优于Fe:LN晶体。 相似文献
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金属涂层光纤适用于极端环境下的探测与信息传输。目前,金属涂层光纤研究主要聚焦于:(1)不同制备方法,包括化学镀法、电镀法、溅射法、蒸镀法和熔融金属法的具体制备工艺,比较不同工艺参数对金属涂层质量的影响;(2)金属涂层光纤涂层质量、力学性能和宏弯损耗性能的表征评价方法;(3)金属涂层光纤的应用场景。本文综述了金属涂层光纤制备方法和性能的研究进展,总结了金属涂层光纤目前存在的问题,为金属涂层光纤今后的科学研究和发展提供参考。 相似文献
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若干无机/有机复合光功能材料及相关器件研究进展 总被引:7,自引:0,他引:7
在无机基质中光学均匀掺杂有机光添生物质以获得复合光功能材料是近年来的研究热点,复合光功能材料的溶胶-凝胶低温合成技术为其在非线性光学、固态可调谐染料激光器、发光显示、光致变色、光化学烧孔等领域的应用提供了可能。本文对无机/有机复合光功能材料的制备技术、结构与性能的表征手段,及其作为发光、激光、波导、波分复用、光致变色器件在光通信中的应用等研究进展作了评述。 相似文献
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J. E. Sohn K. D. Singer M. G. Kuzyk W. R. Holland H. E. Katz C. W. Dirk M. L. Schilling 《Polymer Engineering and Science》1989,29(17):1205-1208
Emerging guided-wave integrated optical technologies require suitable active devices and optical interconnects. Certain organic molecular materials possess the required optical nonlinearities for application in active devices. Glassy polymers, such as poly(methyl methacrylate), have been used to fabricate high optical quality passive structures. For application in integrated optics, requirements include high optical quality (low scattering and absorption losses), low dielectric constant, and suitable fabrication techniques. We describe the preparation and optical properties of a new material, class, poled polymer glasses, which combines the attractive properties of the optical nonlinearities of organic molecules and the optical quality of polymer glasses. These materials are formed by incorporating organic compounds possessing large optical nonlinearities into a host material lacking long-range order. The orientational order is imparted to the composite system by applying a strong electric field at a temperature above the glass transition temperature, where molecular motion is enhanced, thereby aligning the optically nonlinear dopant molecules. By cooling the material through the phase transition with the field still applied, the orientational order is frozen in, and the composite material possesses second-order nonlinear optical properties. 相似文献
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Khalida Messaad Joël Charrier Alexandra Mosqueron Dominique Bosc Philippe Rochard 《应用聚合物科学杂志》2011,121(4):2134-2142
Poly(3‐octylthiophene), (P3OT) in addition to its electronics properties exhibits a high Kerr coefficient, n2, due to its third order nonlinear dielectric susceptibility. At the wavelength of 1550 nm, this coefficient n2 is one of the highest. So, this material should be suitable to build integrated all optical switching devices. To construct this device, it is necessary to make a single‐mode optical waveguide. For the time being, such a P3OT waveguide has never been obtained due to excessive optical losses. In view to produce single‐mode waveguide with P3OT as a core, we investigated the different causes of these optical losses in the material and in the guiding structure. We characterized the optical transmission at key steps in its development. First, we demonstrated that the intrinsic polymer absorption is not a limiting factor at 1550 nm, and then we studied the transmission properties of planar (1‐D confined light) and channel waveguides (2‐D confined light). The results revealed that better transmission properties can be achieved using planar waveguides rather that confined channel waveguides. This article describes the development and the characterization of the guiding structures that enabled us to identify the main origins of optical losses. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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掺杂对铌酸锂光折变响应速度的提高 总被引:11,自引:5,他引:11
在LiNbO3晶体掺入Tb离子,可提高晶体的光折变响应速度。Tb:Fe:LiNbO3晶体既保留了Fe:LiNbO3良好的光折变性能,同时其光折变响应时间大大缩短,可达十几秒,光折变响应速度的提高。可归结为晶光电导的增大,使得晶体内空间电荷场的建立更加迅速。 相似文献