新的质子源质子交换制作的Z切LiNbO3光波导特性

研究了用己二酸和苯甲酸的不同混合摩尔比作为质子源交换制作的Z切LiNbO3光波导的表面折射率改变、波导深度、折射率分布等光学特性。结果表明，在交换温度为230℃，交换时间为6h时，混合摩尔比较高时，波导为β4相；较低时，为β3相。在β4相时，混合摩尔比越大，波导的表面折射率改变和波导的深度越大；在β3相时，不同的混合摩尔比交换的波导光学特性差别不明显。用双晶X射线衍射法对单苯甲酸和混合摩尔比为60％制作的光波导进行X射线衍射。以上结果对波导器件的制作及理解波导折射率改变的物理机制提供了一些有用的信息。     

把LiNbO3浸入苯甲酸-苯甲酸锂混合融体中制备质子交换波导

把X-或Y-切割的LiNbO3晶体放入苹甲酸-苯甲酸锂（0．5～2Mol%）混合体中，于218—248℃的温度范围内制备了质子交换波导。质子变换过程的扩散常数与混合体中苯甲酸锂含量有关。从反W.K.B法算出的折射率剖面表面，不管锂含量多少、交换时间长短以及交换时的温度高低，质子交换层是折射率突变层，其表面折射率均相同。这里也给出了退火后样品的折射率剖面以及对退火样品作第二次质子交换后的折射率剖面．     

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.     

硬脂酸质子交换X切LiNbO3光波导的制备技术研究

利用无毒、无腐蚀性的硬脂酸作为交换质子源, 研究了在X切LiNbO3晶片上制作单模条形光波导的工艺技术。通过对平板光波导的交换及退火特性的研究, 确定了获得单模条形光波导的工艺参数, 制作并测试了条宽不等的X切Y传LiNbO3单模条形光波导。结果表明该工艺条件下制作的条宽为6μm的单模波导实现了小于1dB/cm的传输损耗, 为采用硬脂酸作为交换质子源研制X切Y传LiNbO3集成光波导器件奠定了基础。     

硬脂酸质子交换X切LiNbO3光波导的制备技术研究

利用无毒、无腐蚀性的硬脂酸作为交换质子源,研究了在X切LiNbO3晶片上制作单模条形光波导的工艺技术。通过对平板光波导的交换及退火特性的研究,确定了获得单模条形光波导的工艺参数,制作并测试了条宽不等的X切Y传LiNbO3单模条形光波导。结果表明该工艺条件下制作的条宽为6μm的单模波导实现了小于1dB/cm的传输损耗,为采用硬脂酸作为交换质子源研制X切Y传LiNbO3集成光波导器件奠定了基础。     

质子交换LiNbO3光波导路和Ti扩散LiNbO3光波导的光感应折射率变化的比较

Ti扩散LiNbO3光波导和质子交换光波导路是以各种光器件制作为基础制成的光波导路。不过，在这些光波导路中，特别是在短波长区域，发生折射率随光的入射而变化的光感应折射率变化，这是其实用化的最大障碍。本文测定了上述两个光波导路的光感应     

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．     

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。     

渐变折射率分布MMI型光功分器的研制

以离子交换玻璃波导为例详细分析了渐变折射率分布波导中的自镜像效应,并完成了1×8渐变折射率分布MMI光功分器的设计和特性分析。在理论分析和设计的基础上完成了器件的制作,包括在国产K9光学玻璃上利用K+-Na+离子交换技术和以苯甲酸为交换源在铌酸锂基片上利用质子交换工艺分别完成1×8MMI光功分器的制作。测试表明器件基本实现了光均分功能。     

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。     

A novel wet-etching method using joint proton source in LiNbO/sub 3/

By mixing benzoic and adipic acids as the source of proton exchange, wet etched ridge waveguides are fabricated in Z-cut LiNbO/sub 3/. Under appropriate adipic-benzoic acid concentration ratios, the joint proton source can suppress the proton diffusion in the lateral directions, and thus, the sidewalls are much more vertical than the usual. The etched depths are also enhanced for more than 30%. And meanwhile, the fabricated ridge waveguides possess smooth surfaces and the scattering losses are lower than that of the conventionally produced samples.     

LiNbO3质子交换光波导偏振器的研究

研制了632.8 nm光波段X切Y传Ti扩散铌酸锂质子交换光波导偏振器.从理论上分析了钛(Ti)扩散及质子交换(PE)LiNbO3波导折射率改变机理,以及影响器件性能的各种因素.实验结果与理论计算符合良好,达到了集成光路中对器件的偏振要求,为其他类型偏振器的研制提供了理论依据.     

Proton-exchanged LiNbO3 waveguides: the effects ofpost-exchange annealing and buffered melts as determined by infraredspectroscopy, optical waveguide measurements, and hydrogen isotopicexchange reactions

Infrared spectroscopy in the OH stretching region has been used to determine the extent of proton exchange in x- and z-cut lithium niobate as a function of temperature and time. The behavior observed is consistent with the occurrence of a diffusion-limited process within LiNbO₃. Apparent activation energies for the process determined from infrared spectroscopic measurements are consistent with the existence of a minimum exchange temperature and show that a relationship exists between waveguide depth and absorption band area. The measurements are also shown that hydrogen-bonded OH is substantially removed by annealing and that the extent of its formation is reduced by using buffered (lithium benzoate/benzoic acid) melts. It is suggested that hydrogen-bonded OH groups are responsible for many of the problems associated with proton-exchanged waveguides. Therefore, implementation of either annealing or buffered melts as part of the fabrication process is required to realize good-quality proton-exchanged waveguides     

Ti:LiNbO_3质子交换光波导

本文研究了在Ti扩散LiNbO_3衬底上用苯甲酸质子交换制备光波导的方法,以及单模条件、折射率分布、交换系数、表面状态和热稳定性等问题。     

Optical and structural characterization of Z-cut LiNbO/sub 3/ optical waveguides formed in a mixed proton source

In this paper, the optical and structural characteristics of Z-cut LiNbO/sub 3/ optical waveguides are experimentally investigated. The waveguides have been fabricated by fully immersing the samples in a closed beaker containing a mixture of benzoic and adipic acid at different concentration ratio. The influence of the dilution ratio on crystallographic phases, wavelength dispersion, diffusion coefficient, and index profile has been determined by using infrared absorption spectroscopy and optical characterization. The control of the thickness of guiding layers corresponding to /spl beta//sub 1/ and /spl beta//sub 2/ phases can be realized by varying the dilution ratio of the melt.     

LiNbO3 optical waveguides formed in a new proton source

Proton-exchanged planar waveguides have been fabricated on Z-cut and X-cut lithium niobate crystals by using a new proton source formed by a mixture of benzoic and adipic acids. Waveguide index profiles and optical characteristics have been obtained at different values of the adipic-benzoic acid concentration ratio. The samples have been structurally characterized by Raman and infrared (IR) absorption spectroscopy and double-crystal X-ray diffraction. Good quality samples have been fabricated by using 30 mol% ratio dilution, showing very low scattering levels (<0.1 dB/cm), relatively high electrooptic coefficient (r₃₃=0.88 pm/V), and low relative percentage of interstitial protons (26%). The main factor limiting the waveguide optical properties is the substitutional-interstitial proton ratio, which can be easily controlled to produce good quality waveguides. A demonstration of the repeatability of the exchange process in the acid mixture is also provided     

Nd:MgO:LiNbO_3光波导的制备及其特性

一、引言 目前,LiNbO_3是集成光学系统中使用较为广泛的衬底材料。自从Zhong等人首次报道了掺MgO的LiNbO_3晶体具有抗光损伤效应以来,MgO:LiNbO_3晶体在集成光学系统中得到了越来越广泛的应用。而质子交换MgO:LiNbO_3波导具有比纯LiNbO_3质子交换波导高的抗光损伤能力。把具有较好激光性能的钕离子掺入LiNbO_3中就能制成波导激光器。     

Composition control in proton-exchanged LiNbO3

The amount of hydrogen in Li1?xHxNbO3 layers prepared by proton exchange of LiNbO3 in benzoic acid melts can be limited by adding lithium compounds to the melt. Limiting exchange prevents surface damage, a problem primarily affecting y-cut substrates, and reduces scattering in exchanged guides.