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1.
扩散沟道光波导的数值条形传递函数方法   总被引:1,自引:0,他引:1       下载免费PDF全文
李海阳  周建平  冯莹 《物理学报》2000,49(3):565-569
将数值条形传递函数方法引入了对光波导的计算.该方法将问题域划分为若干条形单元,然后建立离散模型,利用变分原理得到系统的控制方程,最后通过分布参数系统的数值传递函数方法对控制方程求解 关键词:  相似文献   

2.
光波导的条形传递函数无限元解   总被引:1,自引:0,他引:1  
李海阳  周建平  冯莹 《计算物理》2000,17(6):671-677
将无限元引入了条形传递函数方法并用于对光波导的分析。为了对光波导的无穷区域进行处理引入了两种无限单元,一种为解析方向单元,另一种为离散方向单元。在构造无限元的过程中,为了求解方便,利用光波导标量波动方程的特点引入了二阶传递函数解法。最后以矩形波导为例计算并与其他方法进行了比较,结果表明本方法在分析光波导在近截止频率附近的传播特性方面优势明显,并可节省大量的计算。  相似文献   

3.
扩散沟道光波导的条形传递函数解   总被引:2,自引:0,他引:2  
利用条形传递函数方法分析了二维扩散沟道光波导的传播特性,对两种典型折射率分布计算的数值结果与精确解及其它方法的结果进行了比较,表明该方法具有优于其它数值方法的精度.  相似文献   

4.
左手介质椭圆光波导基模传播特性   总被引:1,自引:0,他引:1  
熊天信  杨儒贵 《光子学报》2006,35(7):1099-1102
在椭圆柱坐标系中,采用分离变量方法,得出了左手介质椭圆光波导本征方程的近似解,通过数值计算,分析了椭圆波导偏心率、左手介质的电容率、磁导率对椭圆光波导基模传播特性的影响,并将左介质光波导与右手介质光波导基模特性进行对比,得出左手介质光波导的基模特性与右手介质光波导基模特性差别不大的结论.  相似文献   

5.
扩散平面光波导的传递函数方法   总被引:6,自引:1,他引:5  
引入一种计算光波导传播特性的新方法传递函数方法。给出了公式推导,计算了扩散各向同性及扩散各向异性平面光波导的传播特性,并与其它方法所得结果进行了比较。结果表明用传递函数方法处理折射率渐变分布的光波导问题,计算相对简单,可以得到精确的数值结果。  相似文献   

6.
应用类比法求解介质光波导中场分布的几个实例   总被引:1,自引:1,他引:0  
陈鹤鸣 《大学物理》1998,17(4):6-7,10
利用定态薛定锷方程和介质光波导中亥姆堆兹方程的相似性,分析了类比条件,给出了用类比法求解介质光波导中场分布的几个实例。  相似文献   

7.
通过傅里叶变换将波动方程转化为空间频域的积分方程,并采用Nystrm方法将积分方程转化成标准的矩阵特征问题.通过Lapack程序包求解矩阵的特征值和特征向量,同时得到平面介质光波导模式的色散关系和模式场.数值计算结果表明该方法适用于分析任何折射率分布的平面光波导模式场,使用阶数很小的矩阵就可以得到高准确度的结果.  相似文献   

8.
实验研究了As2S8薄膜光折变现象.提出并采用紫外光激励的方法试制了As2S8条形波导,导模激励显示该波导具有良好的导波特性.在此基础上,考察了As2S8条波导的光阻断效应,实现了光-光效应的开关功能. 关键词: 光波导技术 2S8条形波导')" href="#">As2S8条形波导 光阻断效应 光激励法  相似文献   

9.
本文用加权余量法导出了用以计算各种条形介质波导色散关系,矩形芯双沟道耦合器耦合长度以及条载型波导色散关系的数学表达式,其精确度较其它近似方法高,且简便易行。  相似文献   

10.
金属包层渐变折射率介质光波导的传输特性与损耗   总被引:8,自引:2,他引:6  
佘守宪  谢峰潮 《光学学报》1993,13(4):56-361
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.  相似文献   

11.
Hong Li  Jin-Liang Zhang 《Pramana》2009,72(6):915-925
The auxiliary equation method is very useful for finding the exact solutions of the nonlinear evolution equations. In this paper, a new idea of finding the exact solutions of the nonlinear evolution equations is introduced. The idea is that the exact solutions of the auxiliary elliptic-like equation are derived using exp-function method, and then the exact solutions of the nonlinear evolution equations are derived with the aid of auxiliary elliptic-like equation. As examples, the RKL models, the high-order nonlinear Schrödinger equation, the Hamilton amplitude equation, the generalized Hirota-Satsuma coupled KdV system and the generalized ZK-BBM equation are investigated and the exact solutions are presented using this method.  相似文献   

12.
祝会兵 《中国物理 B》2009,18(4):1322-1327
This paper proposes two lattice traffic models by taking into account the drivers’ delay in response. The lattice versions of the hydrodynamic model are described by the differential-difference equation and difference-difference equa- tion, respectively. The stability conditions for the two models are obtained by using the linear stability theory. The modified KdV equation near the critical point is derived to describe the traffic jam by using the reductive perturbation method, and the kink-antikink soliton solutions related to the traffic density waves are obtained. The results show that the drivers’ delay in sensing headway plays an important role in jamming transition.  相似文献   

13.
In this paper, a generalized time fractional modified KdV equation is investigated, which is used for representing physical models in various physical phenomena. By Lie group analysis method, the invariance properties and the vector fields of the equation are presented. Then the symmetry reductions are provided. Moreover, we construct the explicit solutions of the equation by using sub-equation method. Based on the power series theory, the approximate analytical solution for the equation are also constructed. Finally, the new conservation theorem is applied to constructed conservation laws for the equation.  相似文献   

14.
采用标量概率密度函数(PDF)方法、稳态和非稳态火焰面模型三种方法对一个值班湍流CH_4/O_2/N_2射流扩散火焰(Sandia Flame D)进行数值计算,以比较不同燃烧模型的性能。PDF方法通过计算反应标量的PDF输运方程来得到标量分布,而火焰面模型只求解单标量混合物分数的PDF方程,组分和温度分布通过火焰面方程的求解或者火焰面数据库的插值得到。计算结果和实验数据对比表明PDF方法计算结果最好但计算量相当大,稳态火焰面模型则反之。综合而言,非稳态火焰面模型的预测结果相对稳态模型有了非常大的改进,而计算量仍然容易接受,非常适合工程应用。  相似文献   

15.
The response of Duhem hysteretic system to externally and/or parametrically non-white random excitations is investigated by using the stochastic averaging method. A class of integrable Duhem hysteresis models covering many existing hysteresis models is identified and the potential energy and dissipated energy of Duhem hysteretic component are determined. The Duhem hysteretic system under random excitations is replaced equivalently by a non-hysteretic non-linear random system. The averaged Ito's stochastic differential equation for the total energy is derived and the Fokker-Planck-Kolmogorov equation associated with the averaged Ito's equation is solved to yield stationary probability density of total energy, from which the statistics of system response can be evaluated. It is observed that the numerical results by using the stochastic averaging method is in good agreement with that from digital simulation.  相似文献   

16.
A numerical solution method for two-dimensional (2-D) cochlear models in the time domain is presented. The method has particularly been designed for models with a cochlear partition having nonlinear and active mechanical properties. The 2-D cochlear model equations are reformulated as an integral equation for the acceleration of the basilar membrane (BM). This integral equation is discretized with respect to the spatial variable to yield a system of ordinary differential equations in the time variable. To solve this system, the variable step-size, fourth-order Runge-Kutta method described in Diependaal et al. [J. Acoust. Soc. Am. 82, 1655-1666 (1987)] is used. This method is robust and computationally efficient. The incorporation of a simple middle-ear model can be handled by this method. The method can also be extended to models in which the cochlear partition at each point along its length is represented by more than one degree of freedom.  相似文献   

17.
一类S-mKdV方程族及其扩展可积模型   总被引:2,自引:0,他引:2       下载免费PDF全文
由loop代数的一个子代数出发,构造了一个线性等谱问题,再利用屠格式计算出了一类Liouvelle意义下的可积系统及其双Hamilton结构,作为该可积系统的约化,得到了著名的Schrdinger方程和mKdV方程,因此称该系统为S-mKdV方程族.根据已构造的的子代数,又构造了维数为5的loop代数的一个新的子代数,由此出发设计了一个线性等谱形式,再利用屠格式求得了S-mKdV方程族的一类扩展可积模型.利用这种方法还可以求BPT方程族、TB方程族等谱系的扩展可积模型.因此本方法具有普遍应用价值.最后作为特例,求得了著名的Schrdinger方程和mKdV方程的可积耦合系统.  相似文献   

18.
The purpose of this article (comprising parts I and II) is to develop and test the approach of combining a path-integral technique and a complex-valued Monte Carlo method to calculate the highest moments of the Green function of the stochastic wave equation for a random medium against the background of large-scale inhomogeneities. In part I, the new modified path-integral representations of the Green function moments of the stochastic wave equation have been developed. The limiting transition of these representations to the Feynman path integrals corresponding to the parabolic approximation is discussed. Path-integral representations for Green function moments are given for three models: a model of the stochastic wave equation and models of parabolic and Markov approximations. The Metropolis algorithm underlying the Monte Carlo method for calculating real and complex-valued path integrals is discussed in brief. Numerical results are presented in part II of the article.  相似文献   

19.
Using the wave equation as an example, it is shown how to extend the hydrodynamic Lagrangian-picture method of constructing field evolution using a continuum of trajectories to second-order theories. The wave equation is represented through Eulerian-picture models that are distinguished by their Lorentz transformation properties. Introducing the idea of the relativity of the particle label, it is demonstrated how the corresponding trajectory models are compatible with the relativity principle. It is also shown how the Eulerian variational formulation may be obtained by canonical transformation from the Lagrangian picture, and how symmetries in the Lagrangian picture may be used to generate Eulerian conserved charges.  相似文献   

20.
(2+1)维Camassa-Holm方程的相似约化与解析解   总被引:11,自引:0,他引:11       下载免费PDF全文
郑春龙  张解放 《物理学报》2002,51(11):2426-2430
将Clarkson和Krushal引入的直接约化方法推广并应用到(2+1)维CamassaHolm方程组,获得了该方程的若干相似约化和解析解,其中包括Logistic方程和Bernoulli方程.约化结果得到了Peakon解、Cuspon解和关于时间t的奇异解.该方法也适用于其他有重要物理背景的非线性演化方程 关键词: Camassa-Homl方程 相似约化 直接方法 解析解  相似文献   

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