全硅大断面脊形光波导传播特性的理论分析及实验结果

对当前硅光集成的研究焦点－制备大断面单模脊形光波导的单模条件，用有效折射率法进行分析，也计算了传播常数等性能参数。结果表明，有效折射率法有方法简明、结论确切的优点。它能同时给出单模区、多模区及截止区的条件，已有效指导了ＳＩＭＯＸ及ｎ／ｎ＋外延型两种单模脊形硅光波导的制备。文中最后给出了实验结果。     

硅 SIMOX 单模脊形光波导研制

本文描述硅光波导技术的重大突破：（１）用ＳＩＭＯＸ技术代替传统的硅外延型光波导，解决了衬底吸收光波．从而显著改善了光波导的传播损耗．（２）在理论及实验上均已解决用调整脊形的高宽比（高宽均能达１０微米左右），制取单模脊形光波导．这种光波导的下覆盖层是ＳｉＯ２，传播损耗小；断面积大，和单模光纤耦合良好．满足了光集成技术中对光波导的几项重要要求．     

脊形单模硅光波导的设计

对脊形单模硅光波导的模式特性进行了理论设计。分析了λ＝１．３μｍ的脊形硅光波导的结构参数及工艺流程。这种光波导的数值孔径和单模光纤匹配，传播损耗低于平面条形硅光波导，文中并对传播损耗作了讨论。     

Ge_(0.05)Si_(0.95)/Si脊形光波导的光场分析及设计

利用有效折射率法分析了Ge0.05Si0.95／Si脊形光波导的光场分布，得到了这种光波导在传输单模时内脊高b、外脊高h和脊宽W的合理取值，还为其它光波导器件的设计奠定了基础。     

Ge0.05Si0.9／Si脊形光波导的光场分析及设计

利用有效折射率法分析了Ｇｅ０．０５Ｓｉ０．９５／Ｓｉ脊形光波导的光场分布，得到了这种光波导在传输单模时内脊高ｂ，外脊高ｈ和脊宽Ｗ的合理取值，还为其它光波导器件的设计奠定了基础。     

锗硅脊形光波导Y分支器的模拟及试制

继研制成功单模脊形锗硅合金光波导后，进一步用这种光波导试制Ｙ分支器．文中用束传播法ＢＰＭ首先从理论上分析了波长λ＝１．３μｍ的光波在分支器中的传播特性，模拟计算了模场的传播及损耗．其次叙述了实际锗硅Ｙ分支器的制造工艺及测量结果．结果表明，激光束耦合进锗硅分支器的输入端后，分支器的二路输出端成功输出均匀的单模光波．     

离散谱折射率法优化设计深刻蚀、单模GaAs/GaAlAs脊形光波导

采用离散谱折射率法对深刻蚀GaAs/GaAlAs多层脊形光波导的特性作了详细的理论分析,并对所获得的较大截面、低损耗的单模脊形光波导的制作容差性作了进一步的分析．计算表明,用离散谱折射率法获得的单模脊形光波导具有较大的制作容差性．     

离散谱折射率法优化设计深刻蚀、单模GaAs/GaAlAs脊形光波导

采用离散谱折射率法对深刻蚀 Ga As/ Ga Al As多层脊形光波导的特性作了详细的理论分析 ,并对所获得的较大截面、低损耗的单模脊形光波导的制作容差性作了进一步的分析 .计算表明 ,用离散谱折射率法获得的单模脊形光波导具有较大的制作容差性 .     

单模GexSi1—x脊形光波导的研制

通过分析和计算，得到了单模ＧｅｘＳｉ１－ｘ脊形光波导内脊高、脊宽和腐蚀满足的关系。实践证明，按照这些关系可以成功设计制作 单模ＧｅｘＳｉ１－ｘ脊形光波导。     

非理想截面脊形介质光波导导波模式的研究

提出了一种求解任意截面形状脊形光波导的方法，先利用有效折射率的概念解出某种截面形状脊形光波导的等效折射率，再利用转移矩阵的理论求解出波导的模式色散方程。     

Phase matched magneto optical single mode rib waveguides based on geometrical adjustments

In this work, we demonstrate via numerical simulation the design rules that must be imposed on the geometry of magneto optical rib waveguides to make them behave as single-mode and phase matched rib waveguides.     

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.     

光子晶体粗波分-模分混合复用/解复用器

提出了一种基于光子晶体的粗波分-模分混合复用/解复用器,可在光子晶体上实现波分-模分的一体集成.根据时域耦合模理论,该器件采用点缺陷微腔和波长选择反射微腔的结构实现滤波.根据横向耦合模理论,利用非对称平行波导的结构实现模式转换.应用时域有限差分法对其性能进行分析,仿真结果表明,该器件可以实现1 550nm TE0模、1 570 nm TE0模、1 550 nm TE1模和1 570 nm TE1模四个信道信号的复用和解复用,且具有较低的插入损耗(0.23 d B)和信道串扰(-15.21 d B),该器件在CWDM-MDM中有重要作用,对提升城域网的容量具有重要价值.     

Electro-optically tunable wavelength demultiplexer using depressed index waveguides

A novel configuration of an integrated optical tunable wavelength demultiplexer with a stable channel spacing is proposed. The structure consists of a three-mode depressed index diffused waveguide with single-mode input and output waveguides. The refractive index depression has been designed using experimental data of double diffusion of MgO on Ti:LiNbO/sub 3/ waveguides. The BPM simulation of the structure supports the feasibility of the device and shows a good wavelength tunability.<>     

A proposal on coupled waveguide lasers

a new type of optical oscillator, involving coupled waveguide lasers (CWL's) consisting ofNidentical single-mode active waveguides (N = 3,5) coupled with each other is proposed. Oscillation conditions of coupled waveguide lasers, such as threshold and effective length of waveguides, and output powers are examined theoretically, as compared with the conventional single-mode waveguide lasers.     

Milled-groove method for fiber-to-waveguide couplers

We report a simple milled-groove process integrated with a two-step ion-diffused waveguide fabrication for efficient coupling between single-mode fibers and integrated optical waveguides andY- branches. We demonstrate such a coupling technique using a) a multimode transition to single-mode waveguide coupler, and b) an integrated optical 3-dB branching waveguide coupler from a single-mode fiber to silver/sodium ion-enchanged waveguide components. The coupling loss was about 1-2 dB over a propagation length of 2 cm at an operating wavelength of 633 nm.     

Low-loss single-mode GaAs/AlGaAs miniature optical waveguides withstraight and bending structures

Low-loss single-mode GaAs/AlGaAs miniature optical waveguides fabricated for use in monolithically integrated optical circuits are discussed. The propagation characteristics of these waveguides with straight and S-bending structures have been investigated at wavelengths of 1.30 and 1.55 μm. The lowest propagation losses are estimated to be 0.58 dB/cm and 0.69 dB/cm at wavelengths of 1.30 and 1.55 μm, respectively. The total loss of an S-bending waveguide with a curvature radius of 2 mm and with a lateral displacement of 200 μm was 0.61 dB and 0.46 dB at wavelengths of 1.30 and 1.55 μm. The fabricated single-mode strip-loaded waveguides proved to be suitable for application of the semiconductor waveguide into monolithically integrated optical circuits