多层线型分割法分析渐变型平板介质波导

提出了一种求解渐变折射率平板光波导的传播常数和场强分布的数值计算方法,计算了几类典型的渐变折射率波导的传播常数数值,并与其它方法进行了比较,结果表明,该方法计算的精度极高,速度较快,有实用价值.     

多层线型分割法分析渐变型平板介质波导

提出了一种求解渐变折射率平板光波导的传播常数和场强分布的数值计算方法，计算了几类典型的渐变折射率波导的传播常数数值，并与其它方法进行了比较，结果表明，该方法计算的精度极高，速度较快，有实用价值。     

渐变折射率波导传播特性微扰计算的代数递推公式

应用量子力学的超位力定理（HVT）和赫尔曼－费恩曼（Hellmann-Feynman）定理（HFT），导出了用微扰法计算渐变折射率平面波导传播常数各级近似值的代数递推公式，并给出了由传播常数近似值计算模场近似表达式的代数式。计算了几个典型实例，此法的特点是便于直接计算任意级近似的传播常数及模场分布，且可推广到二维波导的计算。     

金属包覆聚合物平板波导的微扰分析

用理想波导耦合是论为基础的微扰方法分析金属包覆聚合物平板波导,推理波导传播常数的近似解。经数值计算,分别求得传播常数的正确解与近似解,二者相比较,证明近似解具有较高的精确度。从而将求解金属包覆聚合物波导本征值方程的复杂复数运算简化成实数运算。     

任意截面光波导的模式计算

提出了一种计算近理想形状任意截面光波导模式特性的方法。首先运用微扰理论计算出光波导的电磁场分布,然后从麦克斯韦方程出发推导出一个计算光波导传播常数的公式并由此得出其色散曲线,该方法没有繁杂的计算过程。     

用耦合波理论求解渐变折射率光纤的传播常数和模式场

本文应用耦合波理论来计算任意渐变折射李光纤的传播常数和模场分布.将无限伸展的抛物型折射率分布光纤作为一个理想波导,任意径向不均匀折射率分布光纤便可以视作该理想波导的微扰,其模场可以展开成一组完备的理想波导模的叠加.然后,模场和传播常数可以通过耦合波方程求得.进一步将一阶微分方程组形式的耦合波方程变换成线性方程组,使计算过程大大简化.文中给出了数值计算结果,并将其与准确值进行了比较.     

局域波导模展开方法求解梯度型折射率光纤

将阶跃折射率光纤作为一个理想波导,以这个理想波导纤芯一包层的界面为界将横向平面分成两个区域,然后用局域波导模展开方法以及耦会波理论计算了梯度折射率光纤模式场和传播常数.     

Ti∶LiNbO_3二维渐变折射率光波导传播常数的计算

从Ti∶LiNbO3波导截面折射率分布的特点出发，得出一套计算传播常数简单而精确的方法。文中对该法进行了分析，并应用该方法计算了钛扩散波导的色散关系。该方法为钛扩散光波导集成光学器件的设计提供了一种较可靠的理论手段。     

金属包复四层波导结构中的长程表面模

本文从理论上研究了金属包复四层波导中的表面模,指出可以在其中激发长程表面模.用角度扫描衰减全反射方法研究了这种波导中的长程表面模,测量了其传播常数和损耗与波导参数的关系.实验结果和理论计算相符.     

金属包层渐变折射率介质光波导的传输特性与损耗

用金属包层介质光波导损耗的微扰理论及藉助多层近似法用递推公式分析渐变折射率波导传播常数的方法,对几种类型的金属包层渐变折射率介质光波导的传输特性与损耗进行分析和讨论,得到了与精确数值计算结果相吻合的结果.     

钛扩散铌酸锂矩形波导中的双折射耦合对传播常数的影响

 从亥姆霍兹方程出发，得到了各向异性光波导在弱导近似下的耦合模理论。耦合系数包括偏振耦合项和双折射耦合项。并用马卡提里近似下的模式作为零级近似。用一级微扰法计算了折射率渐变分布的钛扩散铌酸锂矩形波导的传播常数。在给定参数的情况下，得到双折射项引起的传播常数的改变约为主微扰项的3%，因此双折射耦合对钛扩散铌酸锂矩形波导的性能影响不可忽略，这对设计和分析与它相关的光波导器件具有指导意义。     

光折变表面波诱导的薄层波导中的导波模式

利用数值模拟对扩散非线性机制下由光折变表面波诱导的薄层波导中导模的形成和特点进行了研究。采用分布傅里叶法对导模的传输特性进行了模拟。通过求解本征方程,对光折变表面波诱导的薄层波导中存在的导波模式进行了数值求解。通过调节传播常数和波导参数的方法,可以控制导模的阶数和传播波形。随着阶数的增加,导模轮廓的对称性越来越差;随着波导参数的增加,导模的峰值振幅单调递增。导模的能量主要聚集在晶体薄层波导中靠近-c轴的一侧,随着传播常数的增大,导模能量先减小后增大,且导模可以稳定传播。     

基于场匹配的任意折射率平板波导ESI参数的分析和计算

首次采用了场的最小二乘方 (LSE)和最小均方误差 (LMS)判据寻找平板波导的等效阶跃折射率 (ESI)模型 ,并通过它预测了平板波导的传输特性。计算结果表明 ,原始波导与等效波导场分布在具有最大近似性的基础上 ,ESI模型可以在一定范围内有效的预测平板波导的传输特性。归一化频率与第一个高阶模的截止频率之比在小于 0 7的情况下 ,用上述两种判据找到的ESI模型预测传输常数相对误差小于 0 0 1 % ,预测归一化传输常数的相对误差小于 1 0 %。     

A new solving method of non-uniform dielectric planar waveguide

A new solving method of non-unifrom dielectric planar waveguide is presented in this paper. By applying this method to solving the problem of planar dielectric waveguide with arbitrary refractive index variation, the advantage of this new method is more evident. By dividing the waveguide into proper numbers and thickness of layers, we can transform the problem of non-uniform dielectric planar waveguide into the multilayer dielectric waveguide to calculate its propagation constantβ.     

掩埋型离子交换玻璃光波导的变分分析

用变分法对离子交换法制备的掺铒光波导的传播特性进行了分析,推导出了适用于掩埋型离子交换玻璃沟道光波导中场分布传播常量的变分表达式,构建了场分布的厄米-高斯型试探解,在两种不同实验条件下,采用变分法确定了试探解中的待定参量,获得光波导中的场分布,利用传播常量的变分公式和已确定的场分布计算得到了传播常量和有效折射率。计算数据表明:导波区域的有效折射率稍稍地大于限制层的折射率,说明离子交换法制备的波导器件是弱波导;高的辅助退火电场强度和适当的退火时间下,所制备的光波导可以支持更多光模式的传输。该方法计算过程简洁、快速,计算结果与实验结果吻合。     

Isolators based on surface waves of Hno type in a rectangular waveguide containing a transversely magnetized ferrite

A solution is presented for propagation of H_no waves in a rectangular waveguide containing a transversely magnetized ferrite plate on one of the sides; the equation for the propagation constant has been solved numerically. Waves of surface type are found to accompany the waveguide type under certain conditions; the calculations define the conditions for these to occur and those for unidirectional propagation. This latter feature in the surface waves is used to design an isolator based on field bias.     

Study of the Leakage Loss in a Silica-on-Silicon Slab Waveguide

A simple and efficient method for studying the leakage loss in a conventional silica-on-silicon planar waveguide is presented. The magnitude of the leakage loss is obtained by calculating the complex propagation constant of the leaky waveguide structure. The dependence of the leakage loss on the thickness of the silica buffer layer (as well as the thickness of the silica upper-cladding layer) is investigated. Numerical results are presented and compared to those calculated with the beam propagation method.     

Enhancement of single mode operation in coaxial optical waveguide using DB boundary conditions

In this study, a competent numerical strategy to compute the dispersion of optical waveguides is presented and propagation of electromagnetic waves in a coaxial optical waveguide with DB boundary conditions is instigated. For this intend, cylindrical coordinates are here being used to derive the DB boundary conditions and to obtain field components for the modes. The propagation constant for the waveguide to be studied is determined by solving the Bessel and the modified Bessel functions. The cutoff frequencies for various lower order modes have been calculated and their dispersion characteristics are plotted correspondingly. The behavior of the coaxial optical waveguide under DB boundary conditions is shown to be significantly different from that of coaxial optical waveguide and conventional optical waveguide under traditional or tangential boundary conditions. Finally, the effect of waveguide dimensions on the mode cutoff frequencies and fabrication issues are also addressed.     

A Simple and Effective Method for Calculating the Bending Loss and Phase Enhancement of a Bent Planar Waveguide

A simple and effective method is introduced to calculate the bending loss and phase enhancement of a bent planar waveguide. The wave field is represented in terms of Airy functions and an eigenvalue equation is derived by matching the boundary conditions and the radiation condition in the outer cladding layer. The complex propagation constant is obtained by solving the eigenvalue equation with the Newton-Raphson method, and the imaginary part of the propagation constant gives directly the bending loss of the bent waveguide. The results are compared with the previous experimental and numerical results and are shown to be highly accurate and effective. The phase enhancement due to the bending is also studied.