On the Theory of Corrugated Optical Disk Waveguides

The corrugated disk dielectric waveguide is investigated by considering a linear combination of orthogonal wavefunctions of the uncorrugated device. It is shown that, just as in the case of corrugated planar slab waveguides, codirectional as well as contradirectional coupling of guided modes is possible. Some potential applications of the device are discussed and device parameters are investigated for specific waveguide materials.     

Acoustic Surface Waveguides and Comparisons with Optical Waveguides

An overview is presented first of the various types of waveguides for acoustic surface waves which have been studied theoretically and experimentally. Many of these waveguides resemble certain waveguiding structures proposed recently for use in integrated and fiber optics. The similarities and differences between corresponding waveguiding structures in the two different fields are then discussed from the standpoints of their properties and their mechanisms of operation.     

平面阵列光学波导模式特性及其光强传输分析

分析了平面阵列波导的模式特性.其导波模式为周期性调幅的平面波(Bloch波).阵列波导输入/输出波导结构是影响其传输特性的重要因素.采用扇形过渡波导结构以提高阵列波导输入/输出端口芯区宽度与波导周期宽度的比值,可降低阵列波导光强的传递损耗.并可改善布里渊区入射/出射波的损耗非均匀性.采用低折射率差的波导芯区/包层结构可降低波导对光波的限制,提高光强的传输效率.     

平面阵列光学波导模式特性及其光强传输分析

分析了平面阵列波导的模式特性.其导波模式为周期性调幅的平面波(Bloch波).阵列波导输入/输出波导结构是影响其传输特性的重要因素.采用扇形过渡波导结构以提高阵列波导输入/输出端口芯区宽度与波导周期宽度的比值,可降低阵列波导光强的传递损耗.并可改善布里渊区入射/出射波的损耗非均匀性.采用低折射率差的波导芯区/包层结构可降低波导对光波的限制,提高光强的传输效率     

Field Solution for Radial Waveguides with Annular Discontinuities

A method is established which gives the internal field of a radial waveguide in the presence of annular-type slots on the conducting walls or metallic scatterers inside the guide. The exciting field can have a general form, and the dielectric constant of the region could be lossy or lossless. To obtain a solution, the induced currents (magnetic current in case of slot-type discontinuity) over the scattering bodies are expanded into a finite series of suitable basis functions with unknown coefficients. The total number of these functions is directly related to the electrical dimensions of the scatterers. The complex coefficients are then obtained by employing the appropriate Green's functions and an application of the boundary conditions over the scattering bodies. The method is then applied to the probIem of coupling between two radials waveguides by annular slots on the common boundary. It is shown that in general, higher order modes have significant effect on the solution, and for a precise evaluation of the field their contribution must also be included.     

硅基SiO2光波导

在硅基上通过氢氧焰淀积的SiO2,厚度达到了20μm;通过掺Ge增加芯层的折射率,折射率比小于1%,并可调;用反应离子刻蚀工艺对波导的芯层进行刻蚀,刻蚀深度为6μm,刻蚀深宽比大于10;波导传输损耗小于0.6dB/cm(λ=1.55μm),并对波导的损耗机理和测试进行了分析与研究.另外,为实现光纤与波导的耦合,结合微电子机械系统技术,在波导基片上制作了光纤对准V形槽.     

Optical Waveguides with Noninteracting Beam-Slope Stabilizers

Ray position in slope-controlled waveguides is studied. A linear combination of three consecutive position measurements is used to calculate the slope error of the middle lens. This is the error input to the middle lens positioning system. Independent lens correction results and thus a decoupling of space and time response is achieved. The system is shown to be stable. Overshoot in the transient response due to cross coupling between controllers is eliminated. Performance is compared to that of the position-controlled waveguide. Computer simulations indicate that the system is stable in the presence of statistical parameter variations.     

硅基SiO_2光波导

在硅基上通过氢氧焰淀积的 Si O2 ,厚度达到了 2 0 μm;通过掺 Ge增加芯层的折射率 ,折射率比小于 1% ,并可调 ;用反应离子刻蚀工艺对波导的芯层进行刻蚀 ,刻蚀深度为 6 μm,刻蚀深宽比大于 10 ;波导传输损耗小于0 .6 d B/ cm(λ=1.5 5 μm) ,并对波导的损耗机理和测试进行了分析与研究 .另外 ,为实现光纤与波导的耦合 ,结合微电子机械系统技术 ,在波导基片上制作了光纤对准 V形槽     

An Alternative Method to Analyze Field Distribution in Curved Dielectric Waveguides

A simple and effective method is proposed to analyze the field distribution of a curved dielectric waveguide with rectangular cross-section. Numerical results are compared with the measured values. It is shown that the present approach is effective and reliable.     

Theory and Applications of Coupled Optical Waveguides Involving Anisotropic or Gyrotropic Materials

Coupled optical waveguides consisting of two isotropic dielectric slab waveguides coupled through anisotropic or gyrotropic materials inserted between them, are treated theoretically in detail. The properties of reciprocal and nonreciprocal TE-TM mode conversion and a nonreciprocal phase shift for TM modes are shown. As an example of application of this type of coupled waveguide, a nonreciprocal optical integrated circuit (IC) mode converter is proposed. It is shown that a circulator and an isolator which require neither mode separators nor mode filters can be constructed by utilizing the proposed nonreciprocal mode converter. The numerical design examples are also given.     

Calculation of Duobinary Transmission Systems with Optical Waveguides

A calculation and optimization method for optical waveguide transmission systems using the principle of digital duobinary transmission is presented. Then, systems with duobinary reception and systems with raised-cosine reception, which also need an equalizer at the receiving end, are compared with regard to the energy per single signal required for a tolerable bit error probability. Other criteria of comparison, such as susceptibility to jitter, additional duobinary system hardware, and error detection facilities, are considered, too. The results of the calculations show that in an optical waveguide transmission system where the duration of the signal at the optical waveguide output exceeds a defined value, the performance of the duobinary system is better than that of the raisedcosine system when the attainable repeater section lengths are compared.     

Microwave Modeling of Optical Periodic Waveguides

A design procedure and experimental method is presented for modeling optical periodic waveguides by means of more convenient parallel plate microwave configurations. These models are suitable for verifying the beam-coupling properties of dielectric gratings that operate in the fundamental TE/sub 0/ surface-wave mode. In particular, blazed gratings with high coupling efficiencies have been constructed and their characteristics have been measured. The results have shown that previously developed design criteria, which are based on a simple Bragg-scattering approach, can yield highly efficient broad-band beam couplers that are not subject to critical fabrication tolerances.     

Finite Element Analysis Waveguides of Optical

A finite element program for the analysis of anisotropic optical waveguides is described. The appearance of spurious numerical modes, due to the fact that the functional is nonpositive definite is discussed and a possible solution to the problem is presented. For isotropic waveguides it is shown that both EH- and HE-type modes can be very accurately approximated by two different scalar finite element programs. Finally, a method for calculating the attenuation of leaky modes in a single material integrated optic waveguide using this scalar finite element method is proposed.     

MOS型波导光学特性分析

本文分析了MOS型波导中金属包层对波导光学特性的影响,给出了TE模传播常数和吸收损耗系数的近似计算公式.为了消除由金属包层引起的吸收损耗,结合计算实例讨论了氧化物缓冲层所需厚度的选择.     

Radiation Fields of Optical Stripline Waveguides

Dispersion characteristics and radiation fields of an optical stripline waveguide radiating into free space are calculated. The waveguides are fabricated as multiple layers of differing dielectric materials. A top layer is etched to form a "cap" with an effective waveguide in a layer below the cap. Confinement of the fields to the waveguide is obtained in the vertical direction by dielectric discontinuities, while lateral confinement occurs because of spatial interference of a continuum of plane waves. The radiation field of the fundamental mode in a plane perpendicular to the waveguide layers is characterized by the layer widths and index discontinuities. Beamwidths of the fundamental mode in the plane parallel to the dielectric layers are developed in terms of the waveguide parameters. Values of these parameters which yield the best optical confinement under the stripe can be obtained.     

Fabrication of DAST Channel Optical Waveguides

In order to use the large, electro‐optic coefficient of a nonlinear optical ionic crystal, 4‐(p‐dimethylaminostyryl)‐1‐methylpyridinium tosylate (DAST), a channel optical waveguide structure is needed. We successfully fabricated a waveguide using two methods: by a dry‐etching technique and by photo‐bleaching. Because DAST has a large optical loss, parts of the waveguide should be composed of a transparent polymer. We used photolithography and a reactive ion etching method to fabricate a serially grafted (conjunct) waveguide of DAST with a transparent polymer waveguide. The waveguide was also fabricated by photobleaching, whereby the refractive indices of the crystal’s a‐ and b‐axes were decreased by degrading the crystal. The cladding part of the DAST waveguide was photobleached by irradiating with UV light. The under‐ and over‐cladding layers of these channel waveguides were composed of a UV‐cured resin that did not dissolve the DAST crystal. The loss of the crystal waveguide for the crystal b‐direction was around 10 dB/cm, due to the scattering loss of the DAST single crystal.     

有机聚合物光波导的研制

聚合物光电子器件是目前世界范围的一个研究热点,其本身所具有易于集成、响应快速、成本低廉一系列优点,在光通信方面有广泛的和极具吸引力的应用前景。介绍了制作有机聚合物光波导的工艺流程,并用两种方法制备出有机聚合物光波导。这对后续研究有很大的帮助。     

Radial Line Band Rejection Filters in Coaxial Waveguides

A coaxial waveguide with a cylindrical cavity forming a double discontinuity in the outer conductor is known to serve as a band rejection filter in the microwave region. A variational principle is applied to calculate the rejection frequency and a subsequent analysis is conducted to determine the dependence of that frequency on various parameters of the structure. Results are presented graphically and by simple analytical formulas. They demonstrate a newly discovered relationship between the rejection frequency and the width of the cavity, and provide design information which enables prediction of the rejection frequency within a 1 percent accuracy.     

Theory of Periodic Dielect Waveguides

The propagation of electromagnetic waves along open periodic, dielectric waveguides is formulated here as a rigorous and exact boundary-value problem. The characteristic field solutions are shown to be of the surface-wave or leaky-wave type, depending on the ratio of periodicity to wavelength (d/lambda). The dispersion curves and the space-harmonic amplitudes of these fields are examined for both TE and TM modes. Specific numerical examples are given for the cases of holographic layers and for rectangularly corrugated gratings; these show the detailed behavior of the principal field components and the dependence of waveguiding and leakage characteristics on the physical parameters of the periodic configuration.     

Single-Mode Pulse Dispersion in Optical Waveguides

The limitations of a widely used method for analyzing pulse distortion in a single-mode waveguiding structure are derived. The results are applied to propagation in optical waveguides, and for cases where material dispersion is dominated by a broad resonance line, pulse attenuation is found to be much more serious than the broadening of the pulse. In extremely low-loss regions, however, other effects may cause the reverse to be true.