质子交换铌酸锂波导MMI光功分器

利用三维非旁轴近似光束传输法对退火质子交换铌酸锂渐变折射率分布波导中的自镜像效应进行分析与模拟 .在此基础上 ,利用退火质子交换技术在 X切 Y传铌酸锂衬底上进一步制作了 1× 8MMI光功分器 .测试表明器件实现了 1路分成 8路的光功分功能 .     

质子交换铌酸锂波导MMI光功分器

利用三维非旁轴近似光束传输法对退火质子交换铌酸锂渐变折射率分布波导中的自镜像效应进行分析与模拟.在此基础上,利用退火质子交换技术在X切Y传铌酸锂衬底上进一步制作了1×8 MMI光功分器.测试表明器件实现了1路分成8路的光功分功能.     

十八酸质子交换铌酸锂光波导的性能及其退火性能的研究

报道了采用十八酸作为质子源制作的铌酸锂光波导的性能及其退火对波导性能的影响，给出了退火前后波导层中非常光有效折射率的剖面分布，得出了质子交换的扩散参数和波导层的表面非常光折射率的增量．给出了波导层的表面非常光折射率的增量和扩散深度的增量与退火时间的指数关系．     

缓冲质子源LiNbO3波导折射率计算及实验

为实现铌酸锂退火质子交换(APE)波导折射率分布的准确计算,选择含苯甲酸锂的苯甲酸缓冲液作为质子交换质子源,高温退火制作了波导样本.针对该工艺过程建立退火质子交换波导模型,包括非线性扩散模块和光学数值仿真模块,分别计算APE波导折射率及其模式有效折射率.以测得的样本波导模式有效折射率和计算的有效折射率差的均方根构建评价函数(FOM),结合遗传算法提取该工艺条件下质子扩散参数,实现了不同交换深度和退火时间波导折射率分布及其光学特性的一体化计算.实验表明:FOM小于0.001,计算折射率分布同IWKB方法测得结果吻合较好,最大偏差约0.002.     

H:LiNbO3光波导

铌酸锂晶体具有良好的光声和电光性质，因而基于铌酸锂的集成光学器件已引起人们的广泛关注。质子交换法是一种制备铌酸锂光波导的重要方法。质子交换铌酸锂光波导具有制作工艺简单，折射率增量大，抗光折变能力强及可实现单偏振激励等特点。本文对质子交换铌酸锂光波导的制作工艺、波导特性及其应用进行了讨论，并指出目前应加强质子交换光波导、质子交换生长动力学和交换工艺的研究。     

质子交换铌酸锂波导的退火工艺

介绍了质子交换铌酸锂波导的制作工艺,比较分析了不同切向、不同退火温度、不同退火时间下铌酸锂波导的特性。     

质子交换铌酸锂波导的退火工艺

介绍了质子交换铌酸锂波导的制作工艺，比较分析了不同切向、不同退火温度、不同退火时间下铌酸锂波导的特性．     

不同切型质子交换弯曲波导的弯曲损耗研究

退火质子交换铌酸锂光波导是一类重要的光波导。对2种不同切型的3种常用S形弯曲质子交换光波导,利用宽角有限差分光束传播法进行了分析。结果表明,3种弯曲波导的弯曲损耗,随波导结构参数的变化基本上是相同的,而在相同的波导结构参数下,X切型的质子交换光波导的弯曲损耗总体上都要小于Z切型的质子交换光波导。数值计算结果为相应波导器件的设计和制备提供了一定的参考。     

铌酸锂光波导制作工艺进展

文章综述了几种常用的铌酸锂波导的制作工艺,包括表面外扩散、金属内扩散、离子交换和质子交换,并分析、比较和总结了在不同工艺制作的条件下对铌酸锂光波导的性能造成的不同影响。目前,获得高质量光波导的主要途径是Ti扩散和质子交换。同时,文章对逐渐建立起的铌酸锂波导光学特性和结构特性之间的理论关系也进行了介绍。     

苯甲酸质子交换LiTaO_3波导及其退火性能的研究

报道了在苯甲酸中制作质子交换ＬＩＴａＯ３光波导的方法和波导的退火特性，给出了退火前后波导层中折射率的分布，计算了波导层的表面折射率增量和扩散系数，结果表明波导层表面折射率增量和退火时间与交换时间的比值有关。     

Characterization of annealed proton exchanged LiNbO3waveguides for nonlinear frequency conversion

A thorough and detailed characterization of annealed proton-exchanged (APE) waveguides in Z-cut LiNbO₃ is described. The mode index measurements in planar waveguides as a function of wavelength and annealing time are reported, including useful analytical relations for the refractive index change, its dispersion, and the depth profile as a function of annealing parameters. Analytical expressions for the mode propagation characteristics are presented and experimentally verified with reasonable accuracy. It is shown that the planar waveguide characterization results can be used to model the channel waveguide characteristics accurately. The model provides closed-form expressions for the mode index and the mode field profile, and the theoretical results are in excellent agreement with the measured data. The technique is used to accurately predict the phase mismatch between the fundamental and second harmonic modes in frequency-doubling experiments using APE channel waveguides. An optimum waveguide geometry for which the phase mismatch is relatively insensitive to the waveguide nonuniformity was predicted and verified experimentally     

条形介质加载型表面等离子体波导传输特性的研究

采用二维时域有限差分(FDTD)法,分析对比了 介质-金属(IM)结构和金属-介质-金属(MIM) 结构波导对光波传输特性的影响,以及通过对IM结构的尺寸、折射率进行优化得到最佳传 输长度。数值 结果表明,IM结构波导能使光波传输距离更长。对IM波导结构研究发现,当介质层厚为 300nm,金属 层厚为200nm时,传输效果最佳。基于这个参数的IM结构,计算介质 层折射率对IM波导光传输特性的影响发现,介质层折射率为1.5时, 在模场约束较好的情况下,传输损耗降低,表面等离 子体波的传输长度最长。整体优化后的条型波导可以实现最大传输距离为37μm。这一设计和优化波导结构 参数的方法不仅拓宽了介质加载型表面等离子体激元(SPP)波导结构的理论基础,在纳米光 学集成器件研究上也具有一定的应用潜能。     

退火质子交换LiNbO3光波导低损耗耦合分析

利用光束传播法分析了退火质子交换铌酸锂光波导模场参数随波导宽度、深度和表面折射率改变的变化情况,指出波导模场受这些参数的综合影响,并讨论了波导结构参数对光纤．波导耦合效率的影响。结果表明,要实现最佳耦合,不同模场直径的光纤对波导结构参数的要求是不同的,这可供相应波导器件的设计和制备参考。     

Singlemode channel waveguides and electrooptic modulators in KTiOPO4 for the short visible wavelength region

Single-mode channel waveguides at short visible wavelengths have been fabricated in KTiOPO₄ by Rb&rlhar2;K ion exchange in mixed melts of RbNO₃-KNO₃-Ba(NO₃)₂ . The technological parameters have been chosen by means of theoretical WKB- and “effective index” calculations concerning the singlemode region of the effective channel waveguide index N₀₀ at the given wavelength. Great diffusion anisotropy and small dispersion of the surface refractive index change guarantee singlemode operation of the very same channel waveguide from the blue up to the red. Typical attenuation of about 2.0 dB/cm for TM- and 1.5 dB/cm for TE polarization was obtained at λ=0.5145 μm. Light-induced refractive index changes (photorefractive effect) have been determined as a function of time, wavelength, guided optical mode intensity and temperature. The light-induced effects in Rb&rlhar2;K ion-exchanged channel waveguides in KTiOPO₄ are about two orders of magnitude smaller than those in annealed proton-exchanged channel waveguides in LiNbO₃. Electrooptic phase modulators have been successfully investigated concerning dynamic V_π measurements, the electric-optical field overlap and dc-drift phenomena. Design, fabrication and experimental results of integrated-optic Mach-Zehnder-interferometer modulators for short visible wavelengths are presented     

Waveguide Filter for Reducing Crosstalk in All Optical Networks

A novel filter structure which can reduce the crosstalk in cross-connection and switching in all optical networks based on dense wavelength division multiplexing(DWDM) is presented.The filter is constructed by dielectric waveguide with the waveguide boundary or the waveguide itself uncontinuous in transmitting direction.Using the concept of effective refractive index of plane waveguide system, we can get a special index profile along the wave propagation direction by alternatively changing the thickness of waveguide film or its refractive index.Having proved this kind of waveguides with filtering properties, the design principle of an example is given, which will be very useful to reduce the crosstalk in optical cross-connection and switching in all optical networks based on DWDM. This kind of filters can be easily connected with other related component.     

Birefringent properties of GaAlAs multiple quantum well planaroptical waveguides

Planar GaAlAs optical waveguides in which the waveguide core region is composed of multiple quantum wells are considered. Calculations of optical waveguide dispersion are performed to determine variations in effective refractive indexes for TE and TM modes and in the mode birefringence for large ranges of total waveguide thickness, number, and refractive index of well and barrier layers, and the ratio of well and barrier layer thickness. Ranges of these parameters which yield optical waveguides having unusually high birefringence and optical waveguides supporting single polarization planar propagation only are identified     

AlGaAs-based two-dimensional photonic crystal slab with defectwaveguides for planar lightwave circuit applications

An AlGaAs-based near-infrared 2-D photonic crystal (PC) with an air-bridge structure featuring defect waveguides has been developed. For the sample without defect waveguides, measurements of the optical transmission characteristics in the wavelength range from 850 nm to 1100 nm showed a deep attenuation due to a bandgap with 30-35 dB attenuation and transmittance of nearly 100% for the guided modes. Optical propagation properties of defect waveguides were obtained by two methods: measurements of transmission spectra and plan-view observations of the optical beam trace along the waveguide with an infrared-vidicon camera. 3-D finite-difference time-domain simulations for the band structure and transmission spectra in the air-bridge slab with and without defect waveguides have revealed the appearance of four defect propagation modes specific to the defect waveguide, between two slab modes for the defect-free photonic crystal slab. These defect modes were experimentally identified in the measured transmission spectra     

Numerical solution of silicon-clad diffused planar optical waveguides

Computer modelling studies indicate that silicon-clad diffused planar optical waveguides exhibit a damped periodic oscillation in their attenuation and phase constant curves and that the attenuation is reduced significantly by reducing the maximum index change.