曲边介质波导的有限元分析

本文应用曲边有限元方法有效地计算了曲边质波导的色散特性，编制了相应的计算程序,应用本文方法计算得到的椭圆旬质波导和组合椭圆介质波导的主模和高次模的色散曲线与文献[2],[3]的结果相当吻合。     

金属包层渐变折射率平板波导传播特性

本文采用多层线型分割近似，结合欧姆损耗微扰法，分析了金属包层渐变折射率平板波导的传播特性，按此方法计算了几类典型波的传播常数数值，结果均与精确值相吻合，且物理概念清楚，计算方法简单。     

用双重场匹配法分析GNRD波导介质带间隙的不连续性

采用双重场匹配法，对ＧＮＲＤ波导的横截面分区，在分区界面用横向的场匹配法计算了波导的传输模和衰减模色散特性及其本征模表达式；并在间隙不连续处用纵向的场匹配法求该处的主模传输系数和反射系数．本文提供的数据可作为ＧＮＲＤ波导多级带通滤波器设计的依据．     

非线性平板介质波导传输特性的网络分析

本文提出了分析包含非线性介质的层状介质波导特性的等效传输线方法，通过把线性和非线性介质分别用等效传输线表示，从而把非线性介质这一复杂的电磁场问题等价成一个电路问题求解，其本征方程可以利用横向谐振原理得到，本文最后分析了层状介质波导包含饱和非饱和非线性介质时ＴＥ模的传播功率与归一化传播常数之间的关系。所获得的结果与有关文献符合得相当好。     

部分填充各向异性介质的圆柱形波导中混合模特性研究

本文首先引入一种新型双向向异性波导结构；给出了这类复杂波导中横向场分量的纵向场表示式以及纵向场分量满足的一组耦合模方程；重点分析了具有不同电磁参数的双各向异性介质中心加载时，金属圆柱形波导中混合模的分裂效应，色散特性和场分布。结果表明，由于多个电磁参数的引入，双各向异性波具有一般各向异性和双各向同性波导结构所没有的新奇特性。     

有耗介质导波结构的高次杂交四边形边缘元分析

本文提出了一种高次杂交四边形边缘元方法。讨论了这种高次杂交边缘元的有限元空间构造，给出了其形函数的显形表达式。这种方法不仅消除了伪解而且能直接求解传播常数，从而无需迭代便能分析有耗介质导波结构的传输特性。对矩形导和条形介质填充波导本征模传播常数的计算表明这种高次杂交边缘元的计算精度比低次杂交边缘元要高出一个量级。     

开波导本征值问题的改进有限元分析

本文提出了一种改进的开波导本征值问题的有限元分析方法。这种方法的基本思想是在内场区域和外场区域之间引入过渡区,并在该区域内选用新的更接近于真实场的场变量模型,从而使离散化过程更为精确,计算效率大为提高。文中通过对若干介质波导色散特性的分析及与以前结果的比较,证实了所述方法的可行性及有效性。     

平面介质光波导的一种矩阵解法

本文将用于多层介质膜堆的矩阵表示方法应用于平面介质光波导中，提出一种简单而适用的获得特征方程的方法。     

四层非线性介质平板中的光波导模

本文讨论了四层克尔型非线性介质平板结构中两种形式的光波导模问题（ＴＥ波），并求得解析解。     

金属栅厚度对介质波导漏波天线辐射特性的影响

本文研究了厚金属栅加载介质插入波导漏波天线的辐射特性，运用电磁场的网络解析法的推广模型建立起本征值方程。数值结果表明，金属栅厚度对漏波天线波束方向影响较小，但对漏波天线的辐射效率和波束宽度有明显的影响。     

Guided-wave characteristics of optical graded-index planarwaveguides with metal cladding: a simple analysis method

The guided mode characteristics of metal-clad graded-index waveguides are generally determined by complex eigenvalue equations or perturbative methods. However, these methods either require several iterations in the complex plane or are only suited to the class of waveguides whose guided field can be described analytically. We describe a method of calculating complex propagation constants for metal-clad graded-index waveguides under very general but weakly guiding conditions. The method, based on Galerkin's formalism using trigonometric basis functions, allows arbitrary inhomogeneous and complex refractive index profiles. Applications to three generally used waveguide models show our approach to be in good agreement with other analytical or numerical methods     

求金属包层平面光波导传播常数的图解法

本文提出一种分别得到金属包层平面光波导传播常数实部和虚部的图解法。这种方法直观、准确而且实用。     

质子交换铌酸锂波导MMI光功分器

利用三维非旁轴近似光束传输法对退火质子交换铌酸锂渐变折射率分布波导中的自镜像效应进行分析与模拟.在此基础上,利用退火质子交换技术在X切Y传铌酸锂衬底上进一步制作了1×8 MMI光功分器.测试表明器件实现了1路分成8路的光功分功能.     

A numerical study of erbium doped active LiNbO3waveguides by the beam propagation method

A numerical investigation of active waveguides realized on lithium niobate crystals using erbium as active element is presented. A software package is implemented to simulate the propagation of electromagnetic waves in graded-index active waveguides using an active vectorial beam propagation method (ABPM), which enables to calculate the optical field evolution along the propagation axis. A comparative study of the optical signal gain evolution as function of erbium concentration profiles obtained by various doping methods is presented. The optimal doping method, leading to the maximum gain, is determined     

Guided wave characteristics of metal-clad graded-index planar optical waveguides: Analytical approach

The complex eigenvalue equations of metal-clad graded-index waveguides are generally solved by numerical methods. The role of waveguide and material parameters in determining mode dispersion and attenuation becomes difficult to elucidate. We describe a perturbative method of solution which is suited to the class of waveguide in which the guided field is described analytically. Mode dispersion and attenuation are explicitly obtained. Applications to three commonly used waveguide models demonstrate the accuracy of our approach in comparison to numerically obtained results.     

Comparison of Absorption Loss in Metal-Clad Optical Waveguides (Short Paper)

A comparison of the absorption loss performance of three types of metal-clad slab waveguides is made with the material and waveguide properties standardized. The basic three-layer configuration of the step-index waveguide and two graded-index waveguides is considered the latter two are also considered as two-layer structures. The comparative loss behavior is discussed from the point of view of application in mode and polarization filtering.     

An efficient scalar finite element formulation for nonlinearoptical channel waveguides

A self-consistent numerical approach based on the scalar finite element method is described for the analysis of both TE-like and TM-like nonlinear guided waves in optical channel waveguides. In order to improve the convergence and accuracy of solutions, isoparametric elements and numerical integration formulae derived by Hammer et al. are introduced. Numerical results are presented for nonlinear elliptical core optical fibers, and it is confirmed that in this approach, highly accurate solutions can be obtained with small scale computation. Furthermore, graded-index nonlinear optical channel waveguides are also analyzed, and the influence of refractive-index profiles on propagation characteristics of the nonlinear guided waves is investigated     

Impedance boundary method of moments for accurate and efficientanalysis of planar graded-index optical waveguides

An impedance boundary method of moments (IBMOM) is proposed to accurately and efficiently compute the propagation characteristics including the number of guided modes of general graded-index dielectric slab waveguide structures. The method is based on Galerkin's procedure in the method of moments and employs the exact impedance boundary condition at the interfaces between the graded-index region and constant-index cladding. Legendre polynomials are utilized in the field expansion. Computational results are shown for waveguides with various inhomogeneous refractive index profiles. The results indicate that typically five Legendre polynomials are sufficient for accurate solutions of the dominant TE and TM modes in optical waveguides having a finite region of inhomogeneous refractive index. Diffused optical waveguides with untruncated index profiles as well as coupled dielectric waveguides can be accurately analyzed using ten Legendre polynomials     

GaAs／GaAlAs截止型光波导调制器的设计

利用近似解析方法，详细地讨论了金属覆盖层介质波导在截止点附近的模式传播特种和截止条件，并结合有效折射率方法讨论了脊高和脊宽对脊形波导截止条件的影响，设计了一种双层质结截止型强度调制器。     

锥形过渡波导的光束传播法分析

基于光束传播法,对几种只沿纵向变化的锥形过渡波导的传输特性进行了分析.分析表明,对同一过渡波导,宽端口输入与窄端口输入时的功率损耗不同,因而应根据过渡波导是宽端口输入还是窄端口输入来选用过渡波导.波导参数对各种过渡波导传输特性的影响也不同.分析结果为各种过渡波导的选用提供了参考.