聚合物波导制备研究

研制出可行的聚合物光波导制备工艺，采用极化电光聚合物NAPA3做芯层和CL－1做包层制作出脊型结构聚合物光波导，波导通光情况良好。     

M-Z型极化DANS聚合物电光波导强度调制器研究

研究了Mach-Zehnder型极化聚合物电光波导强度调制器的制备工艺.器件采用DANS (4-dimethylamino-4′nitro-stlibene)聚合物为电光波导材料,由电光波导层、上下介质缓冲层、上下金属电极层构成五层波导结构.对五层光波导各层之间的光学、化学以及微加工工艺的相互兼容性进行了深入研究.采用紫外光漂白方法制备出侧壁光滑的条波导,采用钨丝电晕极化方法对DANS聚合物波导进行有效极化,使其具有电光特性.通过优化器件制备工艺,研制出工作波长为1300 nm的M-Z型电光波导强度调制器原型器件.实验测得器件半波电压约为10 V,调制带宽约为1 GHz.     

1.5μm Ti:LiNbO_3光波导TE_0模偏振器

在1.523μm波长He-Ne激光,对于Z切Ti扩散LiNbO_3光波导及其带有金属包覆/介质缓冲层的偏振器结构,理论上计算了单模波导的工艺参数和基模的吸收损耗系数.文中用TM_0模的共振吸收效应,在1.5μm波长首次研制成Ti:LiNbO_3光波导TE_0模偏振器.当器件长度为2mm和9mm时,其消光比分别为20dB和25dB.     

硅光波导的束传播法设计及制备

报道用束传播法模拟设计、指导硅大断面单模脊形光波导的制备工艺，应用傅里叶变换法计算了硅光波导中导模的传播常数，对实际研制成功的ＳＩＭＯＸ及Ｓｉ／ＧｅｘＳｉ１－ｘ／Ｓｉ单模脊形光波导，比较了其性能差异并给予理论解释。     

聚合物脊形光波导的变分有效折射率法分析

聚合物脊形光波导是聚合物集成光电子器件的重要构成单元.利用有效折射率法计算聚合物脊形光波导的横向折射率分布及有效折射率,将各区域中的光场分布近似用分段函数表达.基于导模满足的标量波动方程,利用变分法确定变分参量,以求得准确的横向光场分布.对聚合物脊形多模光波导基模和高阶模的色散特性与横向场分布进行分析,研究了波导结构参数对色散特性的影响,计算出TM基模和高阶模的光场分布,得出了聚合物脊形光波导的单模传输条件.研究表明,该方法计算量小、精度高,对聚合物光电子器件中脊形光波导的理论分析与设计优化提供了简单高效的方法.     

硅衬底上锗硅合金光波导的研制

报道锗硅合金在λ＝１．３μｍ的脊形单模光波导的设计，工艺及测量结果。这种光波导的传播损耗已达０．７ｄＢ／ｃｍ。脊形的高４－８μｍ，宽８－１２μｍ，均和单模光纤芯径相当，此外，其数值孔径在光波导的输入，输出端均能和单模光纤匹配，它已满足硅光集成对光波导的要求。文中最后报道了用这种锗硅合金光波导试制Ｙ分支器，并观察到二支分路输出的单模光斑。     

有缓冲层的多层金属包层介质光波导的渐近展开方法

提出求解有缓冲层的多层金属包层介质光波导的一个准解析方法，它应用渐近开展理论将传播常数展开成一个小参数的级数，这一方法本身是精确的，它能达到任意所需的精度，然而四层和五层波导结构的数值计算实例表明，仅二阶近似解就足够精确了。这一方法的优点是简单并且不同层数波导结构以及ＴＥ和ＴＭ膜的解有相同的表达式形式。     

锥形脊结构半导体光放大器的有限元分析

为提高半导体光放大器与单模光纤耦合效率，建立了半导体放大器的锥形脊结构模型。在该模型下利用有限元数值模拟方法分析，计算了波导区折射率、锥尖宽度、条形波导尺寸、渐变折射率波导层对锥形脊结构模式扩展的影响。通过完善锥形脊结构参量的设计，获得了锥形脊结构半导体光放大器与单模光纤95％的耦合效率。     

键合型DANS聚合物光波导电晕极化及其二阶非线性衰减

对键合型DANS聚合物薄膜光波导的电晕极化过程及其二阶非线性衰减特性进行了研究.采用本文给出的电晕极化参数,制成了具有较长极化寿命的极化聚合物薄膜光波导,为进一步研究其二阶非线性光学性质奠定了基础.     

三包层WⅠ和WⅡ型单模光纤波导色散特性的研究

研究了三包层WⅠ和WⅡ型单模光纤的波导色散特性。结果发现在相同条件下，三包层WⅠ和WⅡ型单模光纤零色散点的调节范围比传统的双包层W型单模光纤明显增大。详细分析了几何参量P、Q和光学参量R1、R2对单模传输时的波导色散特性和低次模截止频率的影响。所得的研究结果为获得更为理想的色散补偿、色散平坦光纤及设计新型无源光器件提供了重要的依据。计算波导色散的方法可推广到多包层光纤。     

一种基于导模共振的电光调制器研究

实验研究了基于导模共振的反射型电光调制器采用的棱镜耦合方式,在棱镜上面镀有4层膜,依次为银膜下电极-极化聚合物-缓冲层-金膜上电极。对这种衰减全反射（ATR）型的聚合物波导电光调制器进行了视频调制实验,采用静态偏置电压稳定模式同步角方法,结合对入射激光束进行监测,解决了视频调制中激光器噪声对模拟信号调制影响的问题,提高了工作稳定性。实验结果表明：该电光调制器具有良好的线性和较高的灵敏度。     

Theoretical study of polymeric metal clad optical waveguide polarizer

Planar optical waveguides consisting of thin dielectric films and buffer layers with metal cladding have been investigated theoretically. A computer program was written to calculate the exact zeroes of complex eigenvalue equation for TE and TM modes in multilayer metal clad waveguide polarizer. Numerical results and illustrations are given for Polycarbonate waveguide with other polymers as buffer and Al, Ag and Au as cladding metals at . It is also shown that, using thin (finite) films of metal produce more efficient polarizers as compared to semi-infinite metal films. Effect of low index buffer layer on attenuation of TM/TE modes is also investigated.     

极化聚合物薄膜取向有序度及极化寿命的表征

研究了极化聚事物薄膜波导的退极化过程,提出了表征极化聚合物薄膜取向有序度和极化寿命的集成光学方法。采用集成光学中的棱镜耦合技术,测量极化前后聚合物薄膜光波导的各向异性有效折射率。通过求解各向异性介质光波导的模式本征方程,得到波导极化前后寻常光和非寻常光折射率的变化及其随时间衰减,进而得到取向有序度随时间的变化曲线。采用复合指数函数模型进行最小二乘曲线拟合,进而推测其极化寿命。实验中以键合型ＤＡＮＳ     

Measurement of the optical transmission modes and losses of the poled guest–host polymer NAEC/PEK-c planar waveguides

The polyetherketone (PEK-c) guest–host polymer planar waveguides doped with (4′-nitro)-3-azo-9-ethyl-carbazole (NAEC) were prepared. The waveguide films were poled by corona-onset poling at elevated temperature (COPET), and the corona poling setup includes a grid voltage making the surface-charge distribution uniform. By using the prism-in coupling method, the dark-line spectrum given by the reflected intensity versus the angle of incidence have been obtained, and the optical transmission losses of mth modes have been measured for the poled polymer waveguides at λ=632.8 nm. The measurement result showed that the optical loss of the fundamental mode is less than 0.7 dB cm⁻¹ for the TE polarization.     

侧面抛磨极化光纤的传输特性分析

针对侧面抛磨极化光纤的物理结构，提出了极化光纤的双金属包覆六层波导模型，并对其传输特性进行了分析。分析指出，由于金属电极镀在极化光纤的侧面抛磨平面上，极化光纤中传播的光具有偏振消光特性。对极化光纤的传输特性影响较大的器件结构参量为被抛磨侧面与纤芯的距离，以及紧邻阳极的绝缘胶厚度。     

On the propagation characteristics of metal clad waveguides with a quantum well

The electromagnetic modes of planar metal clad dielectric waveguides containing an n-doped quantum well (QW) are studied theoretically. Special attention is paid on the coupling between metal surface plasmons and intersubband plasmons and the manifestation of this coupling in the propagation characteristics of metal/QW/dielectric and multimode metal/QW/dielectric/metal waveguide structures. The results obtained indicate that the modification of the propagation characteristic induced by the above-mentioned coupling is substantial only in the case of metal/QW/dielectric waveguide structures.     

衰减全反射型电压传感器的理论和实验研究

提出了一种新型反射型聚合物波导电压传感器理论,并且进行了实验研究。这种电压传感器采用棱镜波导耦合结构,在棱镜下底面依次镀有金属膜一聚合物一金属膜三层结构。通过两层金属膜对极化聚合物加电压,利用聚合物材料电光效应和导模共振吸收峰对聚合物折射率的敏感特性,通过反射光强的测量来确定作用电压的变化值。实验中的测试电压范围是从-140V至 140V,得到的线性度值为0．991,电压测量的分辨力为0．1V,电压测量灵敏度系数为0．0011V^-1。实验表明这种电压传感器具有良好的线性和较高的灵敏度。     

Heater optimization for polymer in silica optical switch

An optimization process of specialized heater electrode design for a Multimode Interference (MMI) based polymer in silica thermo-optical switch is described. The switch is designed based on the waveguide structure of photodefinable BenzoCyclobutene (BCB 4024-40) polymer core, sandwiched by a 6 μm thickness of silica (SiO₂) upper clad layer and BK7 glass as a substrate. The upper clad thickness has been chosen such that to avoid any attenuation due to lossy behavior of the metal electrode. The light path is controlled by embedded thermal heater on top of the waveguide at specified location. Starting from a straight rectangular heater at pre-designed location, a migration technique and optimization toward a trapezoidal heater structure has been proposed which utterly claimed a significant improvement in terms of tuning power by more than 15%.