SOI波导弯曲损耗影响因素的分析

采用有效折射率方法EIM(effective index method)和二维束传播算法（2D-BPM）对SOI (silicon-on-insulator）波导弯曲损耗的几种影响因素进行了分析. 通过模拟发现弯曲损耗随弯曲半径的增大、波导宽度的增加及内外脊高比的减小而减小. 同时，改进波导结构，例如在弯曲波导外侧刻槽可以减小SOI脊形波导的弯曲损耗.     

slot波导包覆层对功率密度的影响

理论模拟研究了硅基绝缘(SOI)的slot波导中槽内限制功率与slot波导的结构参数以及包覆层折射率的关系.结果表明,如果包覆层的折射率偏离衬底SiO2的折射率,相同参数下的slot波导的传输损耗大于包覆层为SiO2的结构的传输损耗.分析表明,如果包层与衬底折射率不同,限制的光功率会从slot缝隙中渗透到折射率较高的衬底或者包层中,从而引起能量的损耗.理论模拟得到了在缝隙宽度为0.12μm的情况下,slot波导槽内最大的光功率限制为28.54%,这个值包含了纳米线波导与slot波导直接耦合产生的耦合损耗以及slot波导自身的传输损耗.     

SOI波导弯曲损耗影响因素的分析

采用有效折射率方法EIM(effectiveindex method)和二维束传播算法(2D-BPM)对SOI(silicon-on-insulator)波导弯曲损耗的几种影响因素进行了分析.通过模拟发现弯曲损耗随弯曲半径的增大、波导宽度的增加及内外脊高比的减小而减小.同时,改进波导结构,例如在弯曲波导外侧刻槽可以减小SOI脊形波导的弯曲损耗.     

SOI波导弯曲损耗影响因素的分析

采用有效折射率方法EIM(effectiveindex method)和二维束传播算法(2D-BPM)对SOI(silicon-on-insulator)波导弯曲损耗的几种影响因素进行了分析.通过模拟发现弯曲损耗随弯曲半径的增大、波导宽度的增加及内外脊高比的减小而减小.同时,改进波导结构,例如在弯曲波导外侧刻槽可以减小SOI脊形波导的弯曲损耗.     

用于光互连的聚硅氧烷脊型光波导研究

采用软成型和图案转移技术,制备了可用于高速芯片间光互连的大尺寸聚硅氧烷脊型光波导,光波导长度达23cm.利用有效折射率法,对芯层残留层和传输模场的关系进行了分析.采用截断和数字化散射两种方法,测得输入光波长为633nm时的平均传输损耗小于0.14dB/cm.研究结果表明,波导的长度和损耗指标满足高速芯片间光互连的要求.     

聚合物脊形光波导设计

用5层非对称平面波导理论和等效折射率法(ERIM)分析了金属电极对聚合物脊形光波导横向模式特性及其传输损耗的影响。计算结果表明：在工作波长1．55μm波段,当常规脊形光波导的芯层厚度大于0．8μm、包层厚度大于3．0μm时,才能保证传输损耗的理论极限小于0．1dB／cm;当脊波导刻蚀深度为0.l一0．2μm、对应脊波导宽度为7—5μm时,可满足脊波导横向单模传输。     

聚合物Y分支波导的TM模分析

本文利用有效折射率法计算聚合物脊形波导的横向折射率分布,将三维光波场传播问题简化为二维问题;从导模满足的标量波动方程出发,结合透明边界条件,采用Crank-Nicholson差分格式,得出有限差分束传播法的基本方程.对Y分支波导结构中TM模的传播及损耗特性进行理论分析,得出了优化的结构参数:Y分支角α=1.1°,脊宽W=5μm,波导间距G=20μm.     

硅包层质子交换条形光波导的频率响应

退火质子交换工艺已成为一种制备低损耗铌酸锂光波导的重要技术.但目前对该类光波导传输特性的研究还不多.利用半矢量光束传播法,对硅包层X切退火质子交换铌酸锂条形光波导的频率响应特性进行了数值分析.给出了几种波导结构参数下的计算结果.结果表明,波导传输模式的衰减特性与波长相关.波导的衰减特性,可以通过调整波导表面中心处折射率增量,硅包层厚度,及缓冲层的折射率和厚度来控制.硅包层光波导可以用来制作光频滤波器.     

硅单模脊形光波导的三维模拟及实测结果

对当前硅光集成技术的热点、制备大断面低传播损耗单模脊形光波导进行了三维理论模拟设计。脊的上覆盖层是空气（大折射率台阶，非对称情况）或纯硅层（对称情况），均能得到符合实际的模拟结果。改变脊形光波导的高宽几何尺寸或折射率分布值，模拟结果呈现单模、双模或更高阶模的电场分布及光强分布。用相应条件指导硅脊形光波导的实际制备，实测结果表明模拟结果是准确的。     

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     

Structure optimization of polymeric Mach-Zehnder rib waveguide

The polymeric material is very promising for fabricating the integrated optical waveguide devices. The polymeric op- tical waveguide has become the hotspot because the poly- meric material can offer a series of merits, such as easy integration, rapid resp…     

有双包层结构的楔变脊型光斑转换器的设计

为了提高硅基上单模波导器件与单模光纤的耦合效率和工艺容差,设计了一种实用新型光斑转换器,它由水平和垂直双向楔变的波导芯区和双内包层构成.分析了内包层折射率与其厚度对耦合效率的影响,发现通过优化内包层的参数可以加强对扩展光场的限制.针对在硅基上制作垂直楔变结构的波导还很困难的情况,提出了一种低成本、简单可行的制作方法     

Fabrication of optical inverted-rib waveguides using UV-imprinting

In this paper we introduce a fabrication process for polymer rib waveguides that uses UV-imprint lithography. In the structure of an inverted-rib waveguide, the lower cladding of the waveguide is patterned by UV-imprinting and the waveguiding layer is subsequently spin-coated. That makes the thickness of the formed slab layer on the rib waveguide controllable by tuning the spin-coating parameters. The fabrication process utilizes two steps of UV-imprinting. The first one is to form a rigid polymer mold from positive tone photoresist. The second one is to pattern the waveguide lower cladding with the formed polymer mold. Through the two steps of UV-imprinting, rib waveguides can be fabricated without an etching procedure. We demonstrated the proposed fabrication process by fabricating 2-μm-wide waveguides operating in single mode at 1310 nm. With TE-polarized light, the fabricated waveguides show an average transmission of 58.6% in a 30 mm long waveguide, corresponding to a loss of 2.3 dB.     

Application of the spectral index method to laser diode design

The spectral index method (SIM) is compared to the effective index method (EIM) and the beam propagation method (BPM) for the calculation of the optical mode index and mode profile in a prototypical distributed feedback (DFB) rib waveguide laser diode. Modal index is shown to be insufficient as a metric of comparison, so in addition to n_mode , the quantum well filling factor Γ and grating coupling coefficient κ are included in the metric for comparison. SIM is found to yield superior results to EIM and to give results comparable to BPM almost two orders of magnitude faster     

硅基结构混合等离子激元波导模式特性的数值研究

首先建立了一种由相同宽度的金属带,SiO2间隔层与Si介质脊构成的导体-夹层-硅基结构(Conductor-Gap-Silicon,CGS)的混合等离子激元波导模型,分析了间隔层的厚度以及波导宽度对模式传输特性的影响,提出了模场面积为0.08 m2与430 m传输距离的设计方案.在此基础上,通过增加数值模型中介质脊的宽度而形成硅基板CGS波导结构.数值分析结果表明:硅基板CGS波导可将模式有效折射率增至2.8,同时传输长度能够延长到1.74 mm.并且模场面积可以进一步压缩到0.025 m2.此外,硅基板CGS波导制作更加简便,并可采用现有COMS制作技术完成,进而具有较大的实用前景.     

有双包层结构的楔变脊型光斑转换器的设计

为了提高硅基上单模波导器件与单模光纤的耦合效率和工艺容差,设计了一种实用新型光斑转换器,它由水平和垂直双向楔变的波导芯区和双内包层构成.分析了内包层折射率与其厚度对耦合效率的影响,发现通过优化内包层的参数可以加强对扩展光场的限制.针对在硅基上制作垂直楔变结构的波导还很困难的情况,提出了一种低成本、简单可行的制作方法.     

聚合物环形波导弯曲损耗的改进计算

在大部分集成光学器件中，都会用到弯曲波导，而如何控制波导弯曲产生的损耗。便成了影响这些光学器件性能的关键。应用有效折射率和传输矩阵法相结合，基于matlab平台，数值计算出聚合物PMMA环形波导的弯曲损耗。此外，还针对聚合物PMMA波导制备工艺，提出了通过对包层折射率的修饰，使得弯曲损耗减小的简便方法。这为聚合物PMMA弯曲波导的设计提供了一种有用的优化思路。     

Propagation Properties of a Modified Slot Surface Plasmonic Waveguide

In this paper, we present a modified slot surface plasmonic waveguide formed by metallic rod, core dielectric layer, and metallic film on the substrate. Using the finite-difference frequency-domain method, modal field distribution are analyzed firstly. Results show that the fundamental mode could be well confined in the space between the metal rod and the metal film. The dependence of modal field distribution, effective index, and propagation length of the fundamental plasmonic mode without gain on dielectric constant of the core layer, geometrical parameters, and working wavelengths are analyzed and discussed. A kind of available gain dielectric medium was used for the core dielectric layer to extend the propagation length. Results show that the propagation length can be extended observably with the help of the gain dielectric medium. Finally, effect of the thickness of the core dielectric layer on modal field distribution, effective index, and propagation length are analyzed and discussed. Since the modal field distribution, effective index, and propagation length can be controlled by adjusting the geometrical parameters, dielectric constant and gain of the core layer and working wavelengths of the waveguide, this kind of surface plasmonic waveguide can be applied to the field of photonic device integration and sensors.      

Optimization design of optical waveguide in Mach-Zehnder electro-optical polymer modulator

In order to reduce transmission loss of the optical waveguide in Mach-Zehnder (M-Z) electro-optical (EO) polymer modulator,the basic iterative formula of semi-vector finite-difference beam propagation method (FD-BPM) is obtained from the scalar wave equation. The transition waveguide is combined with S-type bend branch waveguide for the M-Z EO modulator in the branch waveguide. The effects of structure parameters such as ridge width,length of the branch waveguide and interferometer spacing on the transmission loss are systematically studied by using the semi-vector FD-BPM method. The structure is optimized as an S-sine bend branch waveguide,with rib width w=7μm,length of branch waveguide L=1200μm and interferometer spacing G=22 μm. The results show that the optimized structure can reduce transmission loss to 0.083 dB,which have a certain reference value to the design of optical waveguide in M-Z polymer modulator.