铜离子交换单步掩埋BK7玻璃波导的制备与表征

利用Cu离子交换技术制备了BK7玻璃平面光波导,在6328nm波长下,用棱镜耦合技术测量出所制备波导的有效折射率,利用反WKB方法计算并确定了平面光波导的折射率分布,通过对折射率分布进行函数拟合,发现离子交换后的样品折射率分布近似符合改进后的高斯分布,样品的折射率分布似乎是一个掩埋波导的折射率分布,求出所制备玻璃平面光波导在570℃的扩散系数De≈12133×10-14m2s。同时,对所制备波导进行了电子显微镜(EMS)和次级离子质谱(SIMS)测试,得到了铜离子在玻璃表面的浓度分布,从而证明了实验所得到的BK7玻璃平面光波导是掩埋波导。这种掩埋平面波导是由单步Cu离子交换技术得到的。     

Y分支3维光波导横截面折射率分布

为了实现一个表达式同时反映Y分支光波导在纵横两方向上的折射率分布,通过对玻璃结构和离子交换过程进行分析,采用逆向分离变量法提出了基于横向和纵向两个方向折射率分布函数乘积的横截面折射率分布函数,并利用MATLAB软件对优化结果进行了编程模拟。利用Tl+-Na+离子交换法在BK7玻璃基底上制备了Y分支12型3维光波导,利用雅明干涉法对光波导横截面的折射率分布进行了测量。结果表明,利用改折射率分布函数模拟得到的Y分支光波导横截面折射率分布与雅明干涉法实验测得的结果吻合。该改进型折射率分布函数可以对Y分支光波导横截面折射率分布进行模拟,能准确快捷地对Tl+-Na+离子交换Y分支3维光波导横截面折射率分布进行重建。     

高斯折射率分布Cu+-Na+离子交换玻璃波导的制备

利用Cu+ Na+ 离子交换技术制备了玻璃平面光波导 ,在 6 32 8nm波长下 ,用棱镜耦合技术测量出所制备波导的有效折射率 ,利用反WKB方法确定了平面光波导的折射率分布 ,并对折射率分布进行了函数拟合 ,近似符合高斯分布。求出了所制备玻璃平面光波导在 5 80℃的扩散系数为De ≈ 2 2 2 3× 10 -15m2 /s。     

离子交换单模玻璃平面波导折射率分布的确定

用Ag-Na离子交换技术制备了玻璃平面波导.求解扩散方程得到Ag离子在玻璃内部浓度分布.使用一次多项式模拟的方法求解折射率变化与Ag离子浓度变化之间的关系,从而得到了单模平面波导的折射率分布,并验证其与同等实验条件(离子交换时间除外)的多模波导获得的折射率分布函数基本一致.     

Cu离子交换过程对制备玻璃平面光波导特性的影响

用Cu离子交换技术,制备了soda-lime玻璃平面光波导。通过棱镜耦合技术测量了波导的有效折射率,用反WKB方法拟合得到了平面波导的折射率分布。研究发现,离子交换时间和温度2个可控的制备参数对制备的玻璃平面波导特性有较大影响,随着离子交换时间和温度的增加,波导的模式数和波导深度并非随之单调增加,波导模式数随着离子交换时间的增加先增加而后减小,而适当的离子交换时间可以使制备的波导具有最大的模式数和波导深度,且在该条件下增加离子交换温度可以提高Cu离子交换波导的蓝-绿发光强度,宽带发光中心波长在520 nm附近,发光强度取决于样品中Cu+的浓度以及Cu2+的影响。     

电场辅助离子交换制备玻璃光波导

使用电场辅助离子交换和热离子交换技术在玻璃基片上制作了平板波导。实验结果表明,这两种方法制作的波导的有效折射率分布不同,电场辅助离子交换技术制作的波导有效折射率呈近似阶跃型分布,而热离子交换制作的波导有效折射率分布为渐变型。经数值计算发现,近似阶跃型折射率分布的波导对光场限制得更好,更适用于制作有源光器件和集成光器件。     

Cu离子交换波导的制备和折射率分布的表征

用Cu离子交换技术制备了玻璃平面光波导,利用IWKB法与离子浓度计算折射率的方法结合,得到了Cu 和Cu2 相对应的折射率分布.当离子交换深度较深时,折射率变化主要是由Cu 引起,且折射率变化较小;而当深度较浅时,折射率变化则是由Cu 和Cu2 共同作用的结果,而Cu2 的对折射率变化的贡献集中在玻璃表面.通过离子浓度计算得出5 min交换时间的折射率分布呈现准梯度折射率分布形状,而随着离子交换时间的增加所制备的平面波导通过棱镜耦合无法测到波导模式,这可能是由于波导表面折射率下降所致,其机理可能是由于Cu 的外扩散和大离子直径的Cu2 在玻璃表面附近产生的应力在高温下退火被释放的共同结果.     

离子交换玻璃波导的模型分析

对采用BK7玻璃并经过K+ Na+ 二次离子交换法制备的波导 ,用数值求解分析了一次和二次离子交换所形成的折射率分布 ,并分析了影响折射率变化的原因。     

焦磷酸质子交换LiNbO3光波导制备技术研究

采用焦磷酸质子交换技术制备LiNbO3光波导,总结了交换条件、退火工艺和波导特性的实验结果,报告了表面腐蚀情况和单模条件。测量分析了退火前后波导折射率分布的变化,采用循环迭代法拟合折射率分布。结果显示退火前后的折射率分别呈近似阶梯和近似指数的分布,均可用费米函数良好地描述。     

两步离子交换低损耗光波导功分器的研制

报道了在热扩散条件下两步离子交换玻璃光波导功分器的理论分析、样品制作和实验测试.为了便于定量分析,采用了一种上升反正弦S型分支光波导系统的物理模型,得到了在热扩散条件下两步离子交换光功分器波导区的归一化折射率分布和在不同交换时间所形成的玻璃波导折射率分布.在此基础上,设计和制作出第一步采用含Tl 纯熔盐Tl2SO4与玻璃含Na 进行离子交换形成表面下半圆形波导,再把该波导表面脱钛膜放入含Na 熔盐NaNO3中进行第二步离子交换形成掩埋式圆形波导光功分器,实现插入损耗为0.15 dB和分光比为50:50的上升反正弦S型玻璃光波导功分器.     

Fiber-compatible K+-Na+ ion-exchanged channelwaveguides: fabrication and characterization

A systematic study of waveguides fabricated by K⁺-Na ⁺ exchange in soda-lime silicate and BK7 glasses is presented. The measured K⁺ concentration profile, the refractive index profile, and the diffusion profile obtained by solving the one-dimensional diffusion equation are correlated to explain the differences in the index profiles in the two glasses. The mobility of the potassium ions was measured by fabricating waveguides using electromigration. Surface waveguides formed by diffusion from a molten KNO₃ salt bath were buried by applying an electric field. Single-mode channel waveguides for operation at a wavelength of 1.3 μm that exhibit excellent mode matching with conventional optical fibers, achieving a fiber-waveguide insertion loss of less than 1 dB for a 20-mm-long waveguide, have been obtained     

Strip waveguides in LiNbO3fabricated by combined metal diffusion and ion implantation

Embedded strip waveguides in LiNbO3are fabricated by a titanium in-diffusion followed by a masked implantation of helium ions which reduces the refractive index in the unmasked regions and confines the optical wave. This technique yields waveguides with well-defined lateral dimensions and strong optical confinement. The index profiles of helium implanted LiNbO3are determined with an index reduction of more than 1 percent up to about 1 μm depth for 350 keV He+ ions at a dosePhi simeq 10^{16}cm^-2. Electrooptic devices with self-aligned electrodes are fabricated by using the implantation mask as a lift-off mask, and Mach-Zehndet type interferometers are investigated.     

Optical study of porous silicon buried waveguides fabricated from p-type silicon

The realisation of optical buried waveguides fabricated from porous silicon layers is presented. The refractive index of porous silicon layer varies according to its porosity and its oxidisation process conditions. So either step or graded index waveguides are achieved. These waveguides are formed by a localised anodisation of heavily doped p-type silicon wafers. Measurements at a wavelength of 1.3 μm yield waveguide losses below 4 dB/cm. The waveguides are also characterised by the near-field-guided mode profile at 1.3 μm. This study deals with the modulation of the waveguiding-layer refractive index and the losses on waveguides fabricated from p⁺.     

Wavelength dispersion of effective refractive indices of Rb:KTiOPO/sub 4/ optical waveguides

Multimode planar optical waveguides in z-cut KTiOPO/sub 4/ (KTP) substrates have been fabricated using Rb/sup +/:K/sup +/ ion-exchange process. Variations in the refractive index profile and the surface index change with wavelength in these waveguides are approximated by a simple relation. The dispersion characteristics of the effective refractive indices for different guided modes before and after annealing are calculated based on this approximation and the WKB method. Furthermore, the wavelength dispersion can also be expressed using a sellmeier-like equation, and there is an excellent agreement between the calculated values and the measured data.     

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.     

Theoretical modeling and characterization of annealedproton-exchanged planar waveguides in z-cut LiNbO3

Planar optical waveguides in z-cut LiNbO₃ fabricated by the annealed proton-exchange technique using pure pyrophosphoric acid as the initial proton source have been investigated. A generalized Gaussian function was used to accurately model the refractive-index profile, resulting in considerable improvements over previous work. The nonlinear dependence of the index on the proton concentration was verified by directly calculating the change in the area under the index versus depth curves. Annealing was found to allow for flexibility in the tailoring of the waveguide parameters. An empirical correlation of the changes in these parameters with the fabrication conditions was achieved through the use of a general power law     

Waveguides in BK7 optical glass fabricated by transverseelectromigration of silver ions

Low-loss (0.1 dB/cm at 632.8 nm) waveguides fabricated in BK7 optical glass using the transverse electromigration of Ag⁺ ions are discussed. With a migration time of 1.5 h at 320°C, waveguides of depths from 3.0 to 5.0 μm were obtained with various index changes. The inverse WKB method was used to deduce the index profile. The profile was further confirmed by a comparison of experimental and theoretical mode indices and intensity distributions     

High-density integrated planar lightwave circuits using SiO2-GeO2 waveguides with a high refractive indexdifference

GeO₂-doped silica waveguides with a high refractive index difference of 1.5% are successfully fabricated on Si substrates. Their propagation loss, measured in 200-cm-long test circuits with a minimum curvature radius of 2 mm, is 0.073 dB/cm. The waveguides are used as high-density integrated planar lightwave circuits in 1×4 Mach-Zehnder (MZ) type multi/demultiplexers for optical frequency division multiplexing (FDM) transmission systems and in modified MZ type multi/demultiplexers with a ring resonator, which have a compact device size of 15×50 mm² and a frequency spacing of 10 GHz