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．     

全息法研究LN和Mg:LN晶体波导基片的光损伤

本文报道了用全息法研究铌酸锂(LN)晶体和掺镁铌酸锂(Mg:LN)晶体波导基片光损伤的结果。分别采用钛扩散和质子交换工艺制作波导基片;其中Mg:LN晶体波导基片的抗光损伤能力高于LN基片,质子交换波导片的抗光损伤能力高于钛扩散波导片。     

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。     

周期性极化准位相匹配铌酸锂波导中二次谐波的产生

报道了基波波长为 130 0nm的准位相匹配铌酸锂质子交换波导倍频器的实验研制 ,在钛扩散周期性畴反转铌酸锂波导中观测到转换效率为 2 2 %的二次谐波的产生     

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.     

掺MgO的LiNbO_3平面光波导的抗光损伤能力

报道了在质子注入波导中几乎观察不到光损伤。掺镁铌酸锂中质子交换波导的抗光损伤能力是不掺镁的二倍,是钛内扩散波导的8倍。     

LiNbO3电光调制器的优化设计与制作

铌酸锂晶体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广泛关注。利用LiNbO3作为介质材料,设计M-Z干涉型强度调制器。选用低损耗的质子交换光工艺技术制备光波导。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研究。对电极结构进行了优化设计。     

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.     

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.     

Biaxial characteristics of planar proton exchanged lithium niobatewaveguides

Results of a theoretical and experimental study on proton exchanged lithium niobate (LiNbO₃) planar waveguides are presented. Experimental results are successfully explained by the theoretical model only if the guiding layer is assumed to be anisotropic with biaxial characteristics, this biaxiality being induced by the proton exchange process in the uniaxial lithium niobate substrate     

Efficient frequency doubling in reverse proton exchanged lithiumniobate waveguides

We propose a novel approach for efficient frequency doubling of near infrared light, using the coupled system of buried and surface waveguides obtainable by reverse proton exchange in z-cut lithium niobate. In such guides, supporting TM and TE polarizations, respectively, in spite of the use of the d₃₁ nonlinear element, we predict conversion efficiencies as high as 90 or 14% μm/W cm in planar structures excited at 1.32 μm     

Optical waveguide fabrication in neodymium-doped lithium niobate

Reports the realisation of high-quality, proton-exchanged optical waveguide structures in neodymium-doped lithium niobate. Measurements indicate that the presence of the neodymium does not alter the proton exchange rate, and the presence of the protons does not affect the emission and absorption spectra of the bulk material significantly. Such waveguides will permit the realisation of highly efficient semiconductor laser pumped amplifiers and laser structures integrated with electro-optic and/or acousto-optic elements     

Proton-exchanged optical waveguides in Y-cut lithium niobate

The fabrication of proton exchanged monomode optical waveguides on Y-cut lithium niobate is reported. Molten benzoic acid is used, but damage of the crystal surface is avoided.     

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     

利用缓冲质子源制作LiNbO3光波导:光学特性及稳定性研究

利用缓冲质子源(苯甲酸中掺入一定量的苯甲酸锂)在Z切LiNbO3基底上制作了质子交换平面光波导，得到了不同掺杂摩尔分数(0．5％，1．0％和1．5％)的缓冲质子源质子交换波导的有效扩散系数及折射率分布。随着质子源中苯甲酸锂的摩尔含量逐渐增加，质子交换的有效扩散系数呈指数衰减，同时波导表面折射率增量线性递减。研究了有效折射率的稳定性特征，并与用纯苯甲酸制作的光波导进行了比较，发现利用缓冲质子源制作的LiNbO3光波导的稳定性明显优于纯苯甲酸制作的光波导。     

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     

基于热平衡机理的质子交换炉温控系统数学模型

铌酸锂波导集成光学芯片是高精度光纤陀螺系统的核心器件,其性能直接影响光纤陀螺系统的性能。而质子交换炉是用质子交换法制备铌酸锂光波导的主要设备,其炉温的控制质量直接影响铌酸锂光波导的质量。为了实现炉温的精确控制,以炉膛内空气的温度为控制对象,基于热平衡机理建立了质子交换炉温控模型,并在此模型基础上进行了稳定性分析,并利用MATLAB软件对温控模型进行PID控制仿真,结果表明,所建立出来的温控模型是稳定的,但系统采用PID控制时抗干扰能力差,这为进一步研究温度控制策略提供了依据。     

Lithium niobate fibers and waveguides: fabrications andapplications

In this paper, we shall briefly present some recent works done on lithium niobate fibers and waveguides. There are two major parts. The first part introduces the fabrication techniques for LiNbO₃ fibers and waveguides, which include the growth of lithium niobate fibers by laser-heated pedestal growth method and the fabrication of high aspect ratio submicron lithium niobate waveguide by focused ion beam lithography. The second part focuses on the application of lithium niobate fibers and waveguides, which include holographic storage in lithium niobate fibers, fast speed wavelength tunable filter, subpicosecond true time delay line, and low crosstalk microchannel plate spatial light modulator. Finally, a brief summary is provided     

Technological implementation of Bragg grating reflectors in Ti:LiNbO/sub 3/ waveguides by proton exchange

The authors propose and demonstrate a simple and novel method for fabrication of efficient Bragg grating reflectors at telecommunication wavelengths in titanium-indiffused lithium niobate single-mode channel waveguides. This technique is based on the patterned proton-exchanged process. The validity of the method is verified by the good agreement of the spectral responses and the Bragg phase-matching condition. Reflectivity as high as 94% at 1546 nm was measured with 4-mm distributed parameter waveguides in z-cut lithium niobate.