硅,锗透镜磨边双面定中心技术

本文叙述用两台光学定中心仪来观测硅、锗透镜前后表面的球心反射像,并用CCD接收电视屏显示,校正硅、锗透镜的位置,从而达到高精度双面定中心的要求。文中给出了定中心后监视系统装置及实验结果。     

Faraday Optical Isolator/Gyrator Design in Planar Dielectric Waveguide Form

The possibilities of using the magnetic Faraday effect to provide a planar dielectric waveguide isolator or circulator are studied. At least two active elements which couple the TE and TM waveguide modes are required. One of these is magnetooptic. Preliminary design data for a dielectric waveguide isolator in which the mode-converting media forms the substrate and top layer of a single waveguide structure are reported. This design should prove more practical than the optical tandem structures proposed previously.     

Coupling Between an Abruptly Terminated Optical Fiber and a Dielectric Planar Waveguide

The coupling between an optical fiber and a dielectric planar waveguide is analyzed when both guides are terminated abruptly and are facing each other. Mixed spectrum eigenwave representations of fields are employed inside the waveguides while Fourier integrals are utilized to describe the field in the space between the two guides. A coupled system of integral equations is derived by satisfying the boundary conditions on the terminal planes of both waveguides. A weak guidance approximation is assumed to facilitate the analysis. Numerical results are presented for several coupling geometries. Misalignment losses and coupling optimization phenomena are investigated.     

平面波导光传感器的研究进展

高灵敏度的光传感技术在工业过程控制、环境监测、食品安全、国家安全等领域具有重要的应用.随着平面光集成制备技术的发展,光传感器件也从研究开发光纤传感器拓展到便于集成的平面波导光传感器,特别是采用多孔、易掺杂的溶胶一凝胶材料作为化学、生物医学探测的光传感媒介.综述了平而波导光传感器的研究现状与发展趋势,讨论了器件的光传感原理与结构,介绍了其在化学、生物医学、环境检测等方面的虚用.     

Optimizing Dielectric Strips Over a Metallic Substrate for Subwavelength Light Confinement

In this letter, we develop an efficient method for optimizing the geometry of a dielectric strip over a metallic substrate for subwavelength waveguide applications. We investigate the effect of the design parameters on the light propagation and find the optimum design for both loss and light confinement. The proposed design technique generates optimal waveguide geometries that can support single-mode propagation while simultaneously achieving low loss and small modal sizes     

圆锥浸没透镜电子光学系统的研究

本文研究利用边界元素法计算圆锥透镜场分布，用曲傍轴轨迹方程组、实际轨迹方程组追迹计算各种初条件的带电粒子轨迹，确定电子光学参量。其计算结果Ｓ．Ｙａ．Ｙａｖｏｒ等采用渐近解析方法的结果相符。     

非线性锥形梯度折射率透镜的光学特征

本文对非线性锥形梯度折射率透镜进行了分析,根据稳态自聚焦理论以及ABCD定律,导出了高斯光束通过这种透镜光斑尺寸及其位置的公式。讨论了几种特殊的情况,得到了一些重要的结果。     

Planar Spiral in Three-Layer Dielectric with Screen

The excitation of a planar spiral placed in the three-layer dielectric medium in non-symmetric regime have been analysed using the integral representation method. Numerical computations of the patterns, polarization and power characteristics have been carried out for various geometrical and physical parameters. A great influence of the system geometry and dielectric permittivity of the layers on radiated field characteristics has been shown.     

Silicon-on-Insulator-Based Planar Circuit for Passive Optical Network Applications

A novel design of a silicon-on-insulator (SOI) filter for passive optical network applications is described. The SOI filter comprises a monolithically integrated planar reflective grating and a multistage Mach-Zehnder interferometer. The fabricated device showed low insertion losses and high optical isolation. To the best of our knowledge, this letter describes the first demonstration of an SOI circuit comprising monolithically integrated planar reflective grating and cascaded Mach-Zehnder interferometer     

Microwave Irradiation Design Using Dielectric Lenses (Short Papers)

Theoretical calculations and electric-field measurements were made to investigate the focusing effects of plane-wave-irradiated dielectric spheres (lenses). Spheres of different diameters and dielectric properties and plane wave sources of different frequencies were used in the calculations. The results indicate the feasibility of using dielectric lenses for selective partial-body irradiation in biological experiments.     

红外双视场透镜系统的光学设计

对红外成象系统中双视场４片透镜系统的成象原理进行了分析，给出了其高斯求解方程， 对一实例的设计表明该４片透镜系统结构紧凑，成象质量完全满足应用要求。     

Planar Log-Periodic Antennas on Extended Hemishperical Silicon Lenses for Millimeter/Submillimeter Wave Detection Applications

In this paper, the radiation properties of log-periodic (LP) antennas on extended hemispherical dielectric lenses are investigated. The starting point is the far field pattern for the log-periodic antenna on a semi-infinite silicon substrate obtained from numerical simulation. Then the effects of extended hemispherical silicon dielectric lenses on this far field pattern are evaluated using ray tracing and field integration techniques. The far fields patterns out of the lenses are derived as a function of the extension length (L), from which the optimum L can be determined. The coupling efficiencies of the pattern to Gaussian beams are also calculated. The computation results show that the log-periodic antennas have good performance in terms of impedance and pattern and can be used in many submillimeter/THz systems. The simulation methods are verified by comparing the simulation results with experimental data from literature. The utilized approach represents an effective method for log periodic antenna-lens system design at millimeter/submillimeter wavelengths.     

Scattering by Abrupt Discontinuities on Planar Dielectric Waveguides

Two unifying aspects of the problem of scattering by an abrupt discontinuity on a planar dielectric waveguide are considered. The first aspect is concerned with the numerical solution of the scattering problem through consideration of a corresponding bounded waveguide problem in which perfect electric or magnetic conductor bounds with variable locations are introduced. It is shown that the solutions to the bounded problem, when numerically integrated over a range of bound locations defined within half a wavelength, allow the complete mode spectra of the unbounded waveguide to be accurately accounted for. Scattering solutions for both TE- and TM-modes are presented for a wide range of discontinuities and, in the TE-mode case, are in agreement with results obtained using the method due to Rozzi [5]. The second aspect is concerned with the relationship between scattering and "inter-waveguide mode orthogonality." Based on a simple iterative scheme, a meaningful physical interpretation of the scattering process is developed. This allows the scattering to be classified as being of first or higher order, to be explained in terms of the physical characteristics of the mode fields.     

Modal Analysis of a Planar Dielectric Strip Waveguide for Millimeter-Wave Integrated Circuits

A novel planar waveguide which is suitable for guiding electromagnetic (EM) energy in the millimeter-wave and submillimeter- wave regions is studied. By using Wiener-Hopf techniques, we first determine the reflection coefficient at the open ends of the guide. Next, a transverse resonance condition is applied to determine the dispersion relation of the modal field. The propagation constant is found to be complex. Its imaginary part accounts for the edge diffraction loss of the strip through the open ends of the guide. Extensive numerical results are given for the disperson characteristics and modal field distributions for silicon and fuzed quartz substrates. The planar strip waveguide should have the advantages of simplicity in processing, a lower random diffraction loss, and accessibility to monolithic integration techniques.     

非线性介质平板中的光波导模

本文研究了三层克尔型非线性介质平板波导中TE波的传输特性,本问题迄今只有数值解,本文则给出了严格的解析解。     

Light Confinement in Optical Fibers Using Surface Plasmon Polaritons

Efficient light confinement has been demonstrated in a conventional silica optical fiber using surface plasmon polaritons.     

用于平面多层介质结构的全波算法

提出一种平面多层介质带线结构的新型全波算法.该方法基于电场积分方程,由伽略金法求解相应的矩阵方程,从而容易获得表征电路特性的网络参数(如散射参数、导纳).以低温共烧陶瓷(LTCC)带通滤波器为数值算例,并采用Momentum仿真对比,结果表明该方法准确、速度快,可以大大提高格林函数的计算效率.     

供TFT-LCD用的负介电各向异性液晶混合物

包含2,3-二氟化-1,4-次苯基化合物的液晶混合物具有比较大的负介电各向异性、适度的双折射、非常宽的向列范围(-60℃＜T＜85℃)与低的粘-弹系数.这些负介电各向异性对于垂直排列TFT-LCD的应用很有吸引力.     

介质平面光波导TE0模模场分布的高斯近似

基于介质平面光波导端面无受限衍射场光束的光束传输因子的特点,阐明光波导TE0模模场分布采用高斯分布近似表达的合理性。基于场分布间的匹配效率计算公式,提出采用等效匹配效率方法确定用于高斯近似表达的等效模场半宽度,给出基于光波导芯层半宽度和归一化芯层驻波参量和归一化包层倏逝波参量表达的光波导等效模场半宽度的函数表达式,给出高斯近似分布与光波导本征场分布的匹配效率,阐明采用等效匹配效率方法确定等效模场半宽度的合理性。采用求解方程组的方法,给出基于光波导芯层半宽度和归一化频率表达的光波导等效模场半宽度的拟合函数表达式,并基于拟合引起的误差分析阐明了拟合函数表达式的精确性。     

渐变平板表面波天线反射和辐射特性的分析

本文应用有限元和模匹配相结合的方法，采用阶梯近似及阻抗转移技术，分析了渐变平板介质表面波天线的反射和辐射特性。与常规的从场源关系出发来分析辐射问题的方法不同，本文方法从求解介质导波结构的本征值问题入手，从散射的角度将辐射问题转化为表面波和空间波的传输问题，从而使分析过程得到了很大的简化。