K-Na离子交换单模平面波导的制备及其表征

通过K-Na离子交换技术制备了多模玻璃平面波导.采用棱镜耦合技术测量了波导的有效折射率,用IWKB方法拟合得到K-Na离子交换波导的折射率分布符合高斯分布,由色散曲线得到单模波导的制备条件(即扩散深度范围),从而得出单模波导的离子交换时间范围,制备出单模波导,并通过求解WKB色散方程得出单模波导的表面折射率.用普通数码...     

Ag-Na离子交换玻璃波导的折射率分布研究

用Ag-Na离子交换技术制备了玻璃平面波导.通过棱镜耦合技术测量了波导的模折射率,用反WKB方法拟合得到了平面波导的折射率分布为高斯分布.发现Ag-Na离子交换的扩散系数与交换时间有关,并且随着交换时间的增加而减小.使用随离子浓度变化的扩散系数求解扩散方程得到了玻璃内部Ag离子浓度分布,并通过SEM谱证实了求解的正确性;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,得到了平面波导的折射率分布.与反WKB法只能获得多模离子交换平面波导的折射率分布相比,这种方法可以得到任意扩散时间下折射率变化与Ag离子浓度,可以获得单模平面波导的折射率分布.     

数码照相法测量离子交换平面光波导损耗特性

利用数码相机对离子交换平面玻璃光波导传输线进行数字成像,根据传输线上的光强分布拟合出光强传输衰减曲线,计算出波导的传输损耗.对光波导进行退火处理,研究了波导退火前后的传输损耗特性.退火后0阶模式下传输损耗由2.148 9 dB·cm-1降为0.746 0 dB·cm-1.结果表明,波导的传输损耗是随着模阶数的增加而递增,适当的退火处理明显改善了离子交换波导的质量.     

数码照相法测量离子交换平面光波导损耗特性

利用数码相机对离子交换平面玻璃光波导传输线进行数字成像,根据传输线上的光强分布拟合出光强传输衰减曲线,计算出波导的传输损耗.对光波导进行退火处理,研究了波导退火前后的传输损耗特性.退火后0阶模式下传输损耗由2.148 9 dB·cm－1降为0.746 0 dB·cm－1.结果表明,波导的传输损耗是随着模阶数的增加而递增,适当的退火处理明显改善了离子交换波导的质量.     

基于离子交换条波导的生物溶液浓度传感研究

提出并实施了一种实验推定离子交换单模条波导折射率分布的新方法,给出扩散系数可用常量等效的离子交换条件,导出了条波导离子交换制备过程的两维扩散方程的一般解,拟合推定了离子交换条波导的折射率分布.多波长测试的折射率色散通过引入玻璃色散关系解决,样品测试中表征导模吸收损耗的传播常量虚部由KK变换确定.在此基础上,试制了光纤-条波导-光纤一体化传感器结构,验证实测了多种不同浓度的葡萄糖溶液,最低检测限为0.1 μM,实现了低浓度微量测试,验证了条波导传感机制的有效性.     

BK7玻璃保护层掺钕磷酸盐玻璃波导特性

实验研究了基于KNO3稀释AgNO3混合熔盐离子交换法制备的镀有BK7玻璃保护层的N31型掺钕磷酸玻璃平面波导。采用棱镜耦合技术测试了其波导的有效折射率,应用IWBK方法拟合了其折射率分布。实验结果表明:在一定的扩散时间(5～7h)和交换温度(360～380℃)范围内,KNO3与AgNO3混合熔盐比对波导制备的影响起主导作用,引起的表面折射率的变化可达到0.025;BK7玻璃保护层对热离子交换掺钕磷酸盐玻璃表面起到了很好的保护作用,获得了良好的导模传输特性,其光传输损耗约为0.9dB/cm。     

干银膜离子交换玻璃平面光波导

本文采用干银膜离子交换方法,在硅酸盐玻璃表面实现Ag^ -Na^2 离子交换,形成高折射率层,制备出低损耗平面光波导,为玻璃光波导制备提供新的有效技术途径。     

掩埋型离子交换玻璃光波导的变分分析

用变分法对离子交换法制备的掺铒光波导的传播特性进行了分析,推导出了适用于掩埋型离子交换玻璃沟道光波导中场分布传播常量的变分表达式,构建了场分布的厄米-高斯型试探解,在两种不同实验条件下,采用变分法确定了试探解中的待定参量,获得光波导中的场分布,利用传播常量的变分公式和已确定的场分布计算得到了传播常量和有效折射率。计算数据表明:导波区域的有效折射率稍稍地大于限制层的折射率,说明离子交换法制备的波导器件是弱波导;高的辅助退火电场强度和适当的退火时间下,所制备的光波导可以支持更多光模式的传输。该方法计算过程简洁、快速,计算结果与实验结果吻合。     

棱镜耦合法测量掺杂波导模折射率中的误差分析

讨论了棱镜耦合法测量离子交换掺Er-Yb平面光波导中传播模式的模折射率实验中的误差与不确定度,模折射率误差由耦合棱镜折射率与底角及同步入射角误差决定，得出了测量模折射率不确定度的传递公式,作为实例．用Ag^＋-Na^＋离子交换技术,在285℃下交换15min．得到了Er-Yb共掺磷酸盐玻璃平面波导，给出了波导模折射率（@632．8nm）及不确定度。     

确定离子交换平面波导折射率分布的预测-校验法

提出一种基于反WKB法与分段线性插值的最小二乘拟合方法(即预测-校验方法)来确定离子交换玻璃波导的横向折射率分布,它将反WKB法与分段线性插值所计算出的结果作为近似值(预测),然后进行最小二乘拟合(校验),并与基于反WKB的分段线性插值方法进行比较.数值计算表明,这一算法能有效地重建渐变离子交换平面波导的横向折射率分布.     

Investigation of a UV-laser generated planar polymeric waveguide directly and after five years of preparation using an interferometric method

Polymeric integrated-optical waveguides were prepared in a planar chip using UV-laser lithographic method. Five waveguide samples were irradiated by an excimer laser of wavelength 248 nm with different irradiation parameters (fluence and irradiation doses). Using Mach–Zehnder interferometer, the refractive index depth profiles of these samples are determined in two cases, directly and five years later of preparation. A crucial change of refractive indices profiles has been recorded after five years of preparation. In the first case we got double region waveguides fitted a Gaussian shape, while in the second one we observe a single region waveguide which has exponential shape. The photochemical reactions responsible for these changes in the two cases are demonstrated. This is quite important when such waveguides are used in the applications. Also it was interesting to investigate the aging impact on mode field distributions and the effective mode indices. The mode parameters are determined based on a theoretical model and the experimentally obtained data. The results show a notable change in the mode field distributions and the propagation coefficients as influence of aging.     

质子注入掺镱磷酸盐玻璃平面光波导的近红外特性

在能量为(0.5+0.55)MeV和剂量为(1.0+2.0)×10^16 ions/cm^2的条件下,通过氢离子注入制备了掺Yb^3+磷酸盐玻璃波导,并研究了该波导在近红外波段的特性.棱镜耦合法测量的离子注入波导的导模的有效折射率与反射计算法计算的有效折射率基本吻合.通过模拟辐照引起的空位分布,探讨了离子注入平面波导的形成理论.利用FD-BPM对波导中的传播模式进行了模拟,结果表明高能量的氢离子注入掺Yb 3+磷酸盐玻璃能够制备出近红外波导结构.     

掺半导体玻璃波导特性研究

利用离子交换技术制成了单模和多模掺CdSxSe_1-x半导体玻璃波导。通过对波导参数的测量得出这种波导的折射率剖面满足费米函数分布。同时,对这种K⁺—Na⁺离子交换技术得到的单模波导在0.5145μm波长下输入—输出功率的测量,观测到它的功率限制作用。并得到在Ar⁺激光0.5145μm波长下吸收系敲是4cm^-1。在这篇文章中,我们对波导的光功率限制起源于热效应进行了分析和讨论。     

Simplified universal dispersion curves for channel waveguides

Simplified universal dispersion curves for graded-index diffused channel waveguides have been obtained with the new normalized WKB equation using the effective index method. It is shown that, similarly to planar guides, the propagation constant of all the guided modes of a particular channel can be obtained by two parameters, called the normalized mode orders. The dispersion relations between the propagation constant and the normalized mode order of the channel have been obtained for a number of profile shapes and waveguide dimensions.     

Polarization-Independent Guided-Mode Resonance Filters under Oblique Incidence

We present the dispersion relation of guided-mode resonances in planar periodic waveguides, both for s-polarized （TF, mode） and p-polarized （TM mode） incident waves. For a fixed homogeneous planar waveguide, dispersion curves of the TE eigenmode cannot cross that of the TM eigenmode at all. That is to say, at a certain wavelength, TE and TM modes cannot be excited with the same propagation constant. Due to Bragg reflection in the planar periodic waveguide, dispersion curves of the TE leaky mode may intersect with that of the TM leaky mode in the first Brillouin zone. We employ these intersections to achieve polarization-independent guided-mode resonance filters.     

Reconstruction of extraordinary refractive index profiles of optical planar waveguides with single or double modes fabricated by O ion implantation into lithium niobate

A method named intensity calculation method (ICM), which is based on beam propagation method (BPM) and image processing, was carried out to reconstruct the extraordinary refractive index profile (RIP) of single-mode planar waveguide in lithium niobate (LiNbO₃), which was fabricated by multi-energy megaelectron-volt (MeV) O²⁺ ion implantation. In addition, it has been proved reasonable that the alternation of extraordinary refractive index induced by ion implantation into LiNbO₃ is mainly due to the degradation of polarization and reduction of material physical density. As a result, the possible extraordinary RIP of the double-mode planar waveguide could be reconstructed using BPM according to such a hypothesis and the calculated guiding mode values. The end-fire coupling and m-line arrangements were carried out to obtain the near-field modal patterns and dark-mode spectra of waveguides, respectively.     

离子注入石英玻璃光波导的研究

在熔融石英玻璃衬底上,通过注入氮离子和硼离子,制成了低损耗、单模平面光波导.波导的最大折射率和离子浓度分布的半宽度分别是1.48和0.5μm,波导损耗<0.1dB/cm.