共查询到18条相似文献,搜索用时 109 毫秒
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《中国光学与应用光学文摘》2004,(4)
为了在既定尺寸下减小斜坡波导和弯曲波导的功耗,设计了4种过渡波导形状函数,用有限差分光束传播法(FD--BPM)进行了模拟分析,发现过渡波导形状的选取与坡度和曲折角存在条件关 相似文献
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本文主要分析了弯曲波导损耗机理,包括传输损耗、辐射损耗、模式转换损耗。重点综述了设计低损耗弯曲波导的方法,包括波导材料、弯曲波导的曲线形状、波导种类、脊型波导的宽度、脊高、弯曲半径、模场分布、弯曲波导曲线形状和其他新型波导结构等。简要概括了近年来设计和制备低损耗弯曲波导的代表性工作。介绍了弯曲波导在集成光学中的应用。通过对弯曲波导的损耗及耦合机制理论的不断完善,实现光在较小弯曲半径的低损耗传输,从而提高集成光学的集成度是弯曲波导今后的发展趋势。 相似文献
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利用矩形波导和圆形波导的结论,并结合叠加法和镜象法等工具,从理论上分析给出半圆形波导的TE波模型的电磁场分量.根据金属界面的特殊性质,在一定条件下运用叠加法的延拓求出半圆形波导的电磁场分量.最后通过过渡法对一般情况下半圆形波导的电磁场分量进行求解. 相似文献
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根据光线量子理论验证了弱限制波导条件等效于光学中傍轴近似,可将量子理论方法移植到光波导中,并对光线量子力学方法在光波导中应用的物理意义进行了分析和讨论。 相似文献
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利用一维变周期谐振腔阵列和非线性缓变边界,可以实现光波从脊波导到光子晶体平面波导 (PCW)的高效耦合.基于平面波展开法(PWE)和时域有限差分法(FDTD),深入分析和讨 论了普通脊波导、2D-PCW结构和本征模以及工作模式、缓变边界形状等对耦合效率的影响, 从而得出光波从脊波导到2D-PCW、再返回脊波导的统一图景.指出考虑模式转换和采用缓变 边界条件可以极大提高PCW与脊波导间的耦合效率.对PC-PW边界采用线性和非线性缓变结构 进行了仿真,讨论了边界缓变程度对耦合效率的影响.结果表明,采用模式耦合和PC-PW余弦 缓变边界时的耦合效率在较宽的带宽内超过了95%.
关键词:
光子晶体波导
脊波导
PWE
FDTD
耦合边界 相似文献
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本文应用周期介质光波导的模场分布函数和特征方程分析了(Al)GaAs/AlGaAs周期光波导中结构参量及介质折射率对模场分布形状的影响,研究了波导中形成等幅基模的条件,讨论了相应参量的优化选择。 相似文献
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分析了光的线性双折射对磁光波导TE-TM模式转换,法拉第旋转,波导光隔离器隔离比及插入损耗的影响。研究了掺Bi钇铁石榴石薄膜光波导中的形状线性双折射,应力感生线性双折射及生长感生线性双折射的来源,特性和消除方法。 相似文献
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新型低损耗氧化硅Y分支光波导 总被引:8,自引:0,他引:8
提出了一种新型的Y分支光波导结构。该Y分支波导由一个人射波导,一个过渡波导和一对出射波导组成。过渡波导用于改善放射基模与出射偶对称模之间的场分布匹配,有效地提高了功率耦合效率,降低了分支耦合损耗,波束传播法(BPM)数字模拟计算表明,该结构在1.31μm和1.55μm波长下可分别达到0.041dB和0.052dB分支耦合损耗。实验中用等离子化学汽相沉积(CVD)技术制备了SiO2分支波导样品,在上述两波长下分别测得分支耦合损耗为0.08dB和0.09dB,基本达到了设计指标。 相似文献
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A new type of 1 × 3 Y-branch optical waveguide structure with a cone transitional section is introduced in this paper. The symmetrical branch ratio of the 1 × 3 Y branch optical waveguide is obtained by changing the width of this waveguide. The loss and the uniformity are obtained by using the finite difference beam propagation methods, and their values are 0.2 dB and 0.05 dB, respectively. Therefore, it provides some experimental basis for production of three branch optical waveguide. 相似文献
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低插损平坦谱响应阵列波导光栅解复用器优化设计 总被引:4,自引:4,他引:0
通过在输入波导与输入平板波导之间加入一种模式转换结构,获得了一个具有平坦光谱响应,低插损,光谱响应对称的阵列波导光栅型波分复用器,该模式转换结构由一个与输入波导的输出端连接的第一锥形波导,一个与此锥形波导输出端连接的细直波导,一个与细直波导输出端连接的第二个锥形波导以及一个连接输入平板波导和第二个锥形波导的梯形波导组成,通过优化设计梯形波导和第二个锥形波导的形状可以获得较宽的1dB通带带宽和较低的插损,同时光谱响应具有非常好的平坦性,而且通过对第一个锥形波导和细直波导的优化设计,在不引入明显的额外插损的条件下,能大大减小由于输入波导的弯曲引入的光谱响应的不平坦. 相似文献
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Transmission Spectral Characteristics of Photonic Crystals Milled in Annealed Proton-Exchange LiNbO_3 Waveguide 下载免费PDF全文
《中国物理快报》2017,(3)
Transmission spectra of triangular lattice photonic crystals milled in the top surface of an annealed protonexchange waveguide are numerically simulated.The effects of the finite depth,conical shape,trapezoidal shape and hybrid shape of holes are theoretically analyzed.Due to the difficulty of milling high aspect-ratio cylindrical holes in lithium niobate(LiNbO_3),a compromised solution is proposed to improve the overlap between shallow holes and the waveguide mode,and useful transmission spectra with strong contrast and sharp band edges are achieved. 相似文献
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The effect of antimirror reflection from a bounded planar optical waveguide is considered. Earlier, it was used for observing the slow light in a Bragg waveguide. Using the proposed theory of this effect, experimentally observed spectral (Gaussian line shape) and angular (Lorentzian angular distribution) properties of the radiation scattered by the bounded waveguide in the antimirror direction are interpreted. 相似文献
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在SD 对壳模型的理论框架下讨论了原子核形状相变模式。研究结果表明,该理论模型可以把相互作用玻色子模型中U(5)-SU(3)以及U(5)-SO(6) 形状相变模式再现出来,相互作用玻色子模型中有关临界点对称性的特征也可以很好地描述。本文同时也发现原子核从振动到转动的形状相变可以通过改变相互作用强度来实现。The nuclear shape phase transitional patterns were studied in the SD-pair shell model. The results show that the transitional patterns similar to the U(5)-SU(3) and U(5)-SO(6) transitions in the interacting boson model can be produced. The signatures of the critical point symmetry in the interacting boson model are also produced approximately. It is also found that the shape phase transitional pattern between vibration and rotation can also be produced by changing the interactional strength. 相似文献
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Scattering of plane guided waves obliquely incident on a straight feature with uniform cross-section
Wilcox PD Velichko A Drinkwater BW Croxford AJ Todd MD 《The Journal of the Acoustical Society of America》2010,128(5):2715-2725
A frequency-domain finite element (FE) method is presented for modeling the scattering of plane guided waves incident on an infinitely-long, straight feature with uniform cross-section in a planar host waveguide. The method utilizes a mesh of 2-dimensional finite elements with harmonic shape functions in the perpendicular direction. The model domain comprises a cross-section through the feature and short lengths of the adjoining host waveguide. A spatial frequency equal to the wavenumber of the desired incident mode multiplied by the sine of the desired incidence angle is prescribed for the element shape functions. An integral representation of the incident mode is used to determine a suitable system of harmonic forces to uniquely excite that mode. These are applied at nodes through the thickness of the host waveguide on one side of the feature. The displacement field is measured at nodes through the thickness of the host waveguide on either side of the feature and decomposed into reflected and transmitted modes. The cases of guided wave transmission in a featureless waveguide and the reflection of guided waves from a free-edge are examined as validation cases. Finally, the results for transmission at an adhesively-bonded stiffener are presented and compared with experimental measurements. 相似文献