计算平面光栅衍射的一种方法

基于无源均匀媒质中标量电磁场量的平面波展开式 ,获得平面光栅衍射场分布的一般公式 ,其系数由光栅上场分布的傅里叶逆变换得到 ;作为特例 ,给出黑白光栅和正弦光栅衍射场分布的公式 ,与用菲涅耳 基尔霍夫积分公式法得到的结果一致 .     

介质平面波导TE0模衍射场的光束参量

对于傍轴光束，提出了介质平面波导衍射场的近场模场半宽度、远场发散角半宽度和光束传输因子M^2等光束参量之间满足简单的关系式，三个光束参量均可直接由波导模式场分布精确计算，或由可实际精确测量的远场衍射频谱分布精确计算。M^2因子的计算公式可表述为以二阶矩和微分算子定义的近场模场半宽度的比值，或以二阶矩和微分算子定义的远场发散角半宽度的比值。最后推导出介质平面波导TE0模衍射场光束参量的解析函数和光束参量的范围。     

Ta2O5平面波导湿度传感器的研究

本文从应用的角度介绍平面波导传感器的概念及制备方法，在实验的基础上分析和讨论了Ｔａ２Ｏ５平面波导湿度传感器的原理，结构与特性测试方法，为开展集成光学平面波导传感器研究提供理论与技术依据。     

星形光波导耦合器的耦合特性分析

根据TE0模光波导的本征场分布、瑞利索末菲标量衍射积分公式和激励源与光波导耦合的匹配效率公式,给出光波导端面衍射和耦合的归一化发射系数和接收系数计算公式,推导出光波导端面非接触耦合的耦合效率计算公式。光波导模场分布采用高斯函数近似表达,给出简洁的计算光波导端面非接触耦合的耦合效率函数表达式。最后,基于星形光波导耦合器结构参量的特点,将累加运算采用积分运算近似表达,给出星形光波导耦合器接收光波导总的接收效率与耦合器基本参量的关系,阐明了星形光波导耦合器的耦合特性。     

平场输入/输出蚀刻衍射光栅的设计

光通信中波分复用技术是解决通信网络瓶颈的有效手段，近年来得到很大发展。以平面波导波分复用器件为核心的密集波分复用技术已经得到成功商用。蚀刻衍射光栅是平面波导密集波分复用器件中很有发展潜力的一种。原有蚀刻衍射光栅采用罗兰圆设计，输入输出在圆弧曲线上由条形波导引出；而平场输入／输出的蚀刻衍射光栅在很多应用中可以省去制作输入输出波导，大大简化制作工艺，同时能够保持良好的线性色散和聚集效果。给出了平场输入和输出蚀刻衍射光栅的设计方法，并利用标量衍射理论对设计的结果进行模拟，验证了平场输出蚀刻衍射光栅具有很好的分波效果。     

阵列波导光栅复用/解复用器焦场的数值分析

本文利用标量波动衍射理论分析了AWG系统焦场分布,数值计算了阵列波导光栅系统的焦场分布,此方法简便,对器件的优化设计有一定的指导意义.     

阵列波导光栅波分复用/解复用器光谱响应效率的理论模型

基于单模光波导的本征模场分布，瑞利－索末菲衍射积分公式和天线原理的互易定理，给出耦合器中两个非接触平面光波导耦合特性的描述.基此，根据等光程差不等振幅多光束干涉的光场叠加原理，推导出新颖的阵列波导光栅波分复用/解复用器的光谱响应效率的解析函数表达式，这些表达式可为快速精确分析阵列波导光栅波分复用/解复用器的特性提供理论基础.同时,介绍了一个计算阵列波导光栅波分复用/解复用器特性的例子，给出其光谱响应度和信号通道串扰.     

平面波导阵列布喇格光栅及其光辐照制作方法

本文提出了一种新的平面波导阵列布喇格光栅结构,并给出了在光敏感材料中制作这种波导光栅结构的全息光辐照方法.以LiNbO3:Fe晶体作为光敏感材料,用不同空间频率的双光束干涉条纹辐照后,通过数字全息技术对晶体的光致折射率分布测量和进行的导波衍射测试结果表明,利用这种光辐照方法在光敏感材料中制作平面波导阵列全息布喇格光栅是完全可行的.其显著的导波衍射现象表明,如果在平面波导阵列中制作多重布喇格光栅,有可能使其成为超密集波分复用（UDWDM）系统中波长复用/解复用的核心器件.     

高功率平面波导激光器研究进展及分析

平面波导激光器的激光介质既能实现大模体积运转,又在一维方向起到波导作用从而获得高光束质量激光输出,近年来成为高平均功率固体激光器的重要研究方向之一。对国内外平面波导激光器的研究进展进行了归纳总结,对比和分析了平面波导的双包层波导结构、梯形波导结构和自成像结构等结构特点,分析了平面波导结构的发展及趋势,并提出了平面波导激光器发展成为高功率激光器的一些限制因素。     

SiO2波导布拉格器件中声表面波及声光相互作用分析

针对SiO2光波导声光布拉格器件,计算了SiO2非对称平板波导TE模式的横向场分布;给出了SiO2/ZnO/Air层状介质结构的性能方程、运动方程和麦克斯韦方程,推导出这种层状结构的特征方程,并结合所满足的边界条件,得到了各层介质的位移及电磁场分布;计算了声表面波所引起的光学相对介质隔离率张量的变化,最后讨论了声光衍射效率和光场与声场的重叠积分、声功率、声频率、声孔径和光波导参数之间的关系。结果表明,在低频范围内光场与声表面波场重叠良好;低阶模的重叠积分始终大于高阶模重叠积分,最低阶模与声表面波相互作用最强,所需声功率最小;当声功率一定时,增加声孔径可以提高衍射效率。     

基于倏逝场耦合的石墨烯波导光传输相位特性仿真与实验研究

石墨烯材料应用到各种光波导器件中正成为新一代光子器件的重要发展方向之一,目前基于石墨烯的光纤和集成光子器件研究越来越受到国内外的重视. 本文建立了一种由微纳光纤耦合光倏逝场,并在石墨烯薄膜中传输的模型. 通过有限元分析法,研究了光在这种石墨烯波导中传输光场的强度分布和相位特性,并通过实验进行了验证. 结果表明,沿着微纳光纤-石墨烯光波导传播的倏逝场的强度分布和相位均受石墨烯材料作用,石墨烯材料能有效聚集和导行波导中传输的高阶模,在单位传输长度上具有更密集的等相位面. 本文提出了一种利用微纳光纤耦合光倏逝场研究石墨烯相位响应特性的新方法,对基于石墨烯波导的新型调制器、滤波器、激光器和传感器等光子器件的设计和应用具有一定的参考意义. 关键词： 石墨烯平面光波导 倏逝波 光场强度 相位     

Integrated diffractive optical mode converter for fiber-to-waveguide coupling

An integrated diffractive optical mode converter, which can be integrated into planar lightwave circuits (PLCs), consisting of a diffractive optical element (DOE) and a slab waveguide is presented for fiber-to-waveguide coupling. The DOE is designed using iterative phase retrieval algorithm. In the iterative algorithm, we introduce a new modification of far-field amplitude constraint to provide very high mode conversion quality. Compared with previously published mode converters, the scheme is more universal because it is applicable for any waveguide structure. In simulation, coupling losses lower than 0.12 dB have been reached for all the discussed waveguides. The converter is shown to be polarization-insensitive and applicable in multi-wavelength PLCs. And the tolerance on axis misalignment has been investigated.     

Reflection analysis for planar surface wave antennas with different tapering profiles

The reflection characteristics of the planar surface wave antennas with different tapering profiles are analyzed by a method which transforms the radiation problem into the transmission problem of the eigen mode in the partially dielectric filled planar waveguide to avoid the difficulty of the field source problem which is met in the traditional analysis. As a result, the analysis procedure is tremendously simplified. The effect of the tapering profile on the reflection property is carefully investigated and extensive numerical results are given to establish useful guidelines for the design of the planar surface wave antennas.     

对称平面单轴晶体金属波导的模式场(1)

由于平面各向异性介质金属波导的重要应用,本文讨论了光在对称平面单轴晶体金属波导(波导层是单轴晶体,两个波导界面均为金属)内的传输特性.对于晶体光轴位于波导界面法方向与传输方向构成的平面内的特殊波导结构,利用麦克斯韦方程组并结合单轴晶体的性质,精确解出了波导模式场.结果表明:1)此种特殊结构波导内存在横电波(TE)和横磁波(TM);2)TM波的坡印廷矢量与波矢方向不在一条直线上;3)波导层为负单轴晶体时波导主模是TE波主模,而波导层为正单轴晶体时波导主模是TM波主模.     

Guided-mode resonances in multimode planar periodic waveguides

<正>Using the effective medium theory and the waveguide eigenvalue equation,we design a multimode planar periodic waveguide.When a plane wave illuminates the grating at the designed angle and wavelength, more than one leaky modes are excited coincidentally.Then the reflection efficiency around this designed angle and wavelength is investigated using a rigorous coupled wave analysis formulation and a gap of reflection peaks is found.Electric field distributions reveal that this high reflectivity gap is due to the coupling between these two coincidentally excited leaky modes.     

平板波导谐振腔耦合损失的厄米高斯展开分析法

平板波导内的场按自由空间传播的厄米高斯函数展开，计算了平板波导谐振腔的耦合损失，给出了平板波导中ＥＨ１１模的耦合损失与球镜的曲率及位置的关系。结果表明存在两种特定的结构使耦合损失最小。     

Two-dimensional diffraction on a cylinder induced by a laser beam in a nonlinear gradient medium

A wave theory was developed and a numerical simulation performed of the diffractive flow of a signal wave around a negative inhomogeneity induced by a cylindrical pump beam in nonlinear medium while keeping both waves in the potential well. It was shown that a broad pump beam reflects a narrow signal beam. A nonlinear waveguide (a dark soliton) is described as well. These phenomena can be observed in Bose-Einstein condensate (BEC) and in a gradient waveguide.     

A general method for analyzing the multilayer planar waveguide

A general method for analyzing the multilayer planar optical waveguide is presented. This method can also be used to predict the evolution of a wave propagating in the multibranch planar waveguide. The numerical simulation results show that the prediction is correct.     

Symmetric surface plasmon resonance sensing structure excited by a planar waveguide

In this paper, we describe a novel waveguide surface plasmon resonance sensing structure, which consists of a symmetric structure and a planar waveguide. The core component is the symmetric structure of the metal layer, tested sample, and metal layer. The refractive index matching condition of this structure can be adjusted through the thickness of the sample. The planar waveguide is used to excite the surface plasmon wave, and then the parameters are tested and analyzed. The surface plasmon wave is excited when glycerin solutions with concentrations of 0%–70% are used to detect at thicknesses of 300 and 500 nm. The problem that the effective refractive index of the ion exchange planar waveguide is large and using this index to excite the surface plasmon wave between the metal and dielectric for detection is difficult to achieve can be countered by appropriately choosing the thickness of the dielectric in order to be able to measure different refractive indices.