Study of Semiconductor Laser Diode with Circularly Symmetric Waveguide

A semiconductor laser diode with circularly symmetric waveguide is proposed, its property is studied by scalar finite-difference time-domain method (SFD-TDM). The results show coupling loss between the semiconductor laser diode and single mode fiber is reduced effectively, the minimum coupling loss is 0.7 dB.     

3-D Full-Vectorial Analysis of Strong Optical Waveguide Discontinuities Using Pade Approximants

A full-vectorial 3-D numerical method applicable to high-index contrast optical waveguide discontinuities is presented. Rigorous treatment of the longitudinal boundary condition is incorporated in the formulation. The square root of the characteristic matrix is approximated using Padeacute approximants which results in an efficient implementation. The biconjugate gradient stabilized method is utilized to iteratively calculate the reflected and transmitted fields. A preconditioner is proposed which results in reduced number of iterations. The proposed method is applied to various optical waveguide facets exhibiting strong transverse and longitudinal refractive index discontinuities. In all cases, the modal reflectivities of the fundamental TE-Like and TM-Like modes are calculated for both the full-vectorial and the semi-vectorial formulations. Significant difference in the calculated modal reflectivity is seen between the full and semi-vectorial models. The error in the power balance remains low in the full-vectorial case irrespective of the waveguide dimensions. However, in the semi-vectorial case, the error in the power balance is found to increase when the waveguide width is reduced     

对称平板光波导非线性TE波截止值的计算

本文利用解析近似法,研究对称平板光波导非线性TE波的截止特性。导出了计算这种波导截止值的解析公式。结果表明,即使光功率密度很大,我们公式的精度仍很高。     

腔体加载式圆极化波导缝隙天线设计

圆极化天线由于其自身具有的众多优点,在现代通信系统中日益受到广泛关注。设计了一种通过在传统波导缝隙天线上加载旋转矩形腔体实现圆极化辐射的天线形式,分析了腔体辐射圆极化波的机理以及腔体对天线阻抗带宽的影响。该天线具有阻抗特性和圆极化特性独立可调的优点。加工实现了一种工作于X频段、具有1×10个单元的天线结构。测试结果表明,在中心频率处右旋圆极化增益约为16.5 d B,主辐射方向上轴比优于1 d B,阻抗带宽(VSWR<2)约为64 MHz。测试结果与仿真数据取得了较好的一致性。     

Optical Waveguide Modulators

A tutorial survey of recent work on optical waveguide modulators in electrooptic, acoustooptic, and magnetooptic materials is presented. Methods for realizing waveguiding layers in modulating materials and various modulator configurations are considered.     

脊波导缝隙圆极化天线的设计*

设计了一种新型脊波导缝隙圆极化天线。在脊波导宽边开并联纵缝,从波导耦合电磁波至其上方的四脊波导圆极化器,实现圆极化辐射。采用脊波导不仅减小了单元尺寸,更改善了天线的带宽性能。重点研究了四脊波导圆极化器对相互垂直的两辐射场分量的影响,优化单元的轴比特性。在提取单元谐振电导的基础上,设计了工作在10GHz 的1×10 圆极化波导缝隙阵列。对天线实物测试得到中心频率处的增益为16.8dB,第一副瓣电平为 25dB,阻抗带宽约为8.5%,相对轴比带宽(AR臆3dB)约为3.2%。     

LOD-BOR-FDTD Algorithm for Efficient Analysis of Circularly Symmetric Structures

The unconditionally stable locally 1-D (LOD) scheme is used to develop an efficient implicit body-of-revolution (BOR) finite-difference time-domain (FDTD) method. In the LOD-BOR-FDTD, the number of arithmetic operations of the resultant finite-difference equations is significantly reduced, when compared with the alternating-direction implicit (ADI) BOR-FDTD. Numerical results of circular cavity resonators reveal that the LOD-BOR-FDTD provides resonance frequencies identical to the ADI counterparts, with the computational time being reduced to 70%.      

对称线性BiCG迭代法求解波导问题

提出了一种对称化线性双共轭梯度(BiCG)迭代算法,应用于光电工程领域中波导问题的分析。该算法是针对有限元线性系统系数矩阵的大型复对称特性,在常规BiCG迭代法基础上对其进行对称化所得到的快速迭代求解算法。数值结果表明,所提出的对称BiCG迭代法比若干常用方法更加有效。     

Electromagnetic Fields in an Axial Symmetric Waveguide with Variable Cross Section

A new class of separable variables is found which allows one to find an approximate analytical solution of the Maxwell equations for axial symmetric waveguides with slow (but not necessarily small) varying boundary surfaces. Two examples of the solution are given. Possible applications and limitations of this approach are discussed.     

紫外写入技术制备光波导器件研究

研究了采用PECVD方法生长的Si基SiO2波导材料的光敏特性.经过高压载氢处理,利用KrF准分子激光脉冲(工作波长为248nm)在波导材料中诱导出的折射率变化量达到0.005,相对值约增加0.34%.详细研究了紫外光诱导出的折射率变化沿样品深度方向的分布情况.最后,采用紫外写入法在PECVD方法生长的Si基SiO2波导芯层中制备出了单模波导和Y分束器样品,并观测到了通光现象,实测结果与模拟结果一致.     

紫外写入技术制备光波导器件研究

研究了采用PECVD方法生长的Si基SiO2波导材料的光敏特性.经过高压载氢处理,利用KrF准分子激光脉冲(工作波长为248nm)在波导材料中诱导出的折射率变化量达到0.005,相对值约增加0.34%.详细研究了紫外光诱导出的折射率变化沿样品深度方向的分布情况.最后,采用紫外写入法在PECVD方法生长的Si基SiO2波导芯层中制备出了单模波导和Y分束器样品,并观测到了通光现象,实测结果与模拟结果一致.     

指数型光波导的近似解析法

本文用一级微扰理论，对指数型折射率分布光波导，进行了波方程的解析求解，推得用Ａｉｒｙ函数表示的场解和色散方程。用一级近似计算了传播常数（β／ｋ）ｍ，与Ｃｏｎｗｅｌｌ的精确计算相比较，其结果也是好的。     

Circularly Polarized Electric Field in Rectangular Waveguide (Short Papers)

The electric field in a waveguide partially filled with a low-loss slab of dielectric in the H plane presents a Circularly polarized component at the air-dielectric interface over a limited frequency range. This effect could be used to improve the performance of nonreciprocal devices utilizing the gyroelectric effect in magnetized semiconductors.     

全硅片上光互连用波导

较详细地分析了用于全硅片上光互连所用光波导（如多晶Si／SiO2、Si／SiO2、Si3N4/SiO2）需满足的基本条件、制作方法以及损耗机制,总结了目前的研究进展。     

半导体光波导开关列阵

光波导开关是光网络的基础器件。半导体中的电光效应、能带填充效应、多量子阱的量子限制Stark效应以及等离子体色散效应等都可分别被利用来制作成光波导开关。本文综合介绍基于上述效应的光波导开关的发展动态。     

A Three-Cavity Circularly Polarized Waveguide Directional Filter Yielding a Maximally Flat Response

A directional filter is a completely matched four-port device which exhibits directional properties and a filter-like frequency characteristic. This paper extends work previously done on a single-cavity narrow-band circularly polarized waveguide directional filter to the case of three cavities connected in cascade with an overall bandwidth greater than 1 per cent. Analysis of the filter leads to a relationship between the two inner coupling factors and the two outermost coupling factors for a maximally flat response. The results obtained from an experimental filter using the design approach discussed herein compare favorably with the theoretical filter response. Directivity and band-elimination filter characteristics are discussed.     

Properties of Symmetric Hybrid Waveguide Junctions (Correspondence)

In his letter J.M. Smith states that in a fully symmetric lossless hybrid where all arms are matched, the amplitudes of the waves traveling in the reverse direction in the main and auxiliary guides are equal. To allow for the existence of the reflected waves this theorem should read: "In a slightly imperfect symmetric hybrid with matched loads on the output ports the amplitude of the reflected wave at the input port is equal to the amplitude of the wave at the isolated port."     

一种Ka频段高效率圆极化宽角扫描波导缝隙相控阵天线

该文提出一种新型小尺寸、低剖面、"f"字型波导缝隙圆极化器,高度仅1/6波长,宽度约2/5波长.基于该圆极化器,设计了一种高效率、低剖面、圆极化脊波导缝隙线阵天线.为满足空间应用中对轻质、高效率、圆极化、±60°宽角扫描相控阵天线的需求,采用该线阵天线作为阵元设计、仿真并实现了16阵元Ka频段脊波导缝隙相控阵天线.仿真和实测结果表明,该相控阵天线可实现1维±60°宽角扫描.在扫描角范围内,相控阵天线的轴比小于4.1 dB,增益下降小于4.3 dB.在0°扫描角工作时,天线的实测增益为35.9 dBi,辐射效率接近85％.     

一种Ka频段高效率圆极化宽角扫描波导缝隙相控阵天线

该文提出一种新型小尺寸、低剖面、“f”字型波导缝隙圆极化器,高度仅1/6波长,宽度约2/5波长。基于该圆极化器,设计了一种高效率、低剖面、圆极化脊波导缝隙线阵天线。为满足空间应用中对轻质、高效率、圆极化、±60°宽角扫描相控阵天线的需求,采用该线阵天线作为阵元设计、仿真并实现了16阵元Ka频段脊波导缝隙相控阵天线。仿真和实测结果表明,该相控阵天线可实现1维±60°宽角扫描。在扫描角范围内,相控阵天线的轴比小于4.1 dB,增益下降小于4.3 dB。在0°扫描角工作时,天线的实测增益为35.9 dBi,辐射效率接近85%。     

光波导用氟化物玻璃薄膜

系统回顾了光波导用氟化物玻璃薄膜的研究历史,总结了其制备方法与研究现状,重点介绍了氟化物玻璃薄膜在无源光波导和有源光波导上的应用,并对其前景进行了展望.