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利用耦合张量对光折变旋光,电光,压电及弹光铋硅族氧化物晶体中光波本征模的作用,在任意晶体切割面上求解了弱耦合的矢量波耦合方程, 并利用有效耦合概念处理了非旋光晶体 中的矢量波耦合问题. 进而计算旋光和非旋光材料中信号光的增益, 并分别比较各向同性耦 合和各向异性耦合对增益的影响. 对旋光材料优化增益,并把处理结果应用于BSO和BTO晶体 . 还讨论了压电和弹光效应对(110),(111)及(112)切割面优化增益的影响.
关键词:
铋硅族氧化物
光折变
旋光效应
压电
弹光效应 相似文献
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磁光材料是现代光通信产业中不可或缺的关键功能材料。为了实现光通信器件的小型化,高质量磁光薄膜材料受到关注。软铋矿型Bi25FeO40具有高对称性的立方晶体结构,单位体积所含铋离子浓度高,理论上应具有较强的磁光效应,但却因为磁性偏弱、制备困难等缺点而限制了其应用。本文采用射频磁控溅射法,在掺钇二氧化锆(YSZ)基底上沉积获得具有立方相软铋矿型结构的Bi26-x-yMxNyO40 (M, N=Fe, Co, Gd)磁光薄膜,并对其形貌、磁性、透过率、磁圆二色信号等进行表征。结果表明,薄膜均较为平整,厚度约为190 nm,在近红外区的透过率约为60%~70%。薄膜的磁性随着掺杂离子含量的提高逐渐增强。Bi13.6Gd2.7Co4.0Fe5.7O40/YSZ薄膜具有强磁光效应,在716 nm处的磁圆二色光谱信号高达到1 710 deg/cm,有望应用于集成光隔离器等光通信器件中。 相似文献
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T. O. dos Santos J. F. Carvalho A. C. Hernandes 《Crystal Research and Technology》2004,39(10):868-872
The synthesis of Bi2O3‐Nb2O5 sillenite phase (BNbO) and the solubility of this phase with Bi12TiO20 was investigated by solid‐state reaction synthesis and niobium doped Bi12TiO20 (BTO:Nb) crystals were grown by the Top Seeded Solution Growth (TSSG) technique. The structures of polycrystalline compounds were checked by X‐ray powder diffraction method at room temperature. The correct composition of the sillenite phase stabilized with niobium was determined as Bi12[Nb0.17Bi0.83]O19.7 (BNbO) with unit cell parameter a = 10.261(2) Å. The system BTO‐BNbO is poorly soluble, but niobium doped BTO crystals were grown from the liquid composition 10Bi2O3 : xTiO2 : (1‐x)/2 Nb2O5, with x = 0.95 and 0.90. A niobium concentration limit in the liquid phase is established in order to grow BTO:Nb with good crystalline quality. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Bi12TiO20 (BTO) single crystals doped with PbO and CeO2 were grown by the Top Seeded Solution Growth (TSSG) technique from the liquid phase with nominal compositions of 10Bi2O3 : (1–x)TiO2 : x PbO and 10Bi2O3 : (1–x)TiO2 : xCeO2 with x = 0.25 and 0.10. No growth‐related difficulties were encountered other than those typical of sillenite crystals. Samples with good optical quality were obtained and were characterized by optical absorption, dark current, spectral photocurrent dependence, optical activity and electro‐optic coefficient measurements. A comparison is made of the results of the optical measurements of doped and undoped BTO crystals. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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This work presents a holographic interferometer that uses the photorefractive sillenite crystals in diffusive regimen whose configuration exhibits diffraction anisotropy for real-time holographic interferometry. The writing–reading process of holographic interferogram was done in real-time, connected with an interferogram-analysis method that uses the phase-stepping technique for quantitative measurement of changes on an object. The holographic interferograms from the analyzed surface were captured and they were used to calculate the phase map with four-frame technique. The unwrapping process used was the cellular-automata technique. We obtained quantitative results for some applications: measurements of micro-rotation of surfaces, punctual micro-displacements on an aluminum plate, stress on a dog's jaw, among others; adding new promising applications possibilities for basic research, dentistry and technological areas. 相似文献
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The structure and thermal behavior of metastable solid solutions with nominal compositions Bi2PbO4, Bi4HgO7, Bi12TlO19.5, and Bi12Cd0.7O18.7 with the sillenite structure obtained by mechanochemical treatment in a planetary mill (thermal decomposition of the metastable Bi4CdO7 phase with a bcc structure above 700 K) have been studied. The large Pb2+ atoms occupy up to ~30% positions in the sillenite structure (Hg2+ and Hg(1) occupy up to ~15% of (24f) positions). The (2a) sites are partially occupied by bismuth with a minor shift along the [111] axis and are transformed into the (8c) site, forming an umbrella structure with c.n. 3. The relatively small Cd2+and Tl3+ cations partially occupy the (2a) sites. During annealing, the metastable Pb-sillenites are partially stabilized with a loss of oxygen and increasing content of bismuth. Sillenite with a high content of lead retains its structure until it melts at 923 K. Cadmium sillenite reacts with CdO, passing into a rhombohedral structure at 900 K (30 K below the melting point). Mercury sillenite Bi4HgO7 decomposes with isolation of metallic mercury at ~600 K.Original Russian Text Copyright © 2004 by V. V. ZyryanovTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 480–490, May–June 2004. 相似文献
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This work proposes to obtain surface contouring by phase-shifting real-time holography using photorefractive sillenite crystals which provides the surface contouring from a change in phase of wavefront of the object illumination beam. The real-time holography using the photorefractive Bi12SiO20 crystal and the four-frame phase-shifting technique was used to obtain the phase map, this map was filtered by an anisotropic sin/cos filter and the unwrapping process used was the cellular-automata technique. We obtained experimental results of the surfaces of the large objects with real discontinuities, and these results agree with the dimensions of the object. 相似文献
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The boron sillenite, up to now known as the 12:1 compound Bi24B2O39 in the system Bi2O3 – B2O3 andcrystallizing in the space group I23, melts incongruently at 655 °C only about 25 K above the eutectic tie line and corresponding to a steep liquidus line. Single crystals with dimensions larger then 1 cm 3 have been successfully grown in [100], [110], and [111] direction by an improved Top Seeded Solution Growth (TSSG) technique equipped with crucible weighing, accelerated crystal rotation technique and air‐cooled pulling rod. The structure of the boron sillenite was analyzed by X‐ray diffraction method, which was possible due to the high crystalline quality achieved. A defect‐free sublattice corresponding to a Bi‐O framework is isostructural with all sillenites, but a 2 Å environment around the origin is occupied by different cations with different population coefficients. The best calculation results in the formula Bi24.5BO38.25 which is more Bi‐rich than the 12:1 assumption. 相似文献
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