低阈值极化电压玻璃光波导的电光效应研究

采用热极化技术对掺锗玻璃条形光波导进行极化,并通过光纤连接(单模)的Mach Ze-hnder Interferometer系统测量波导内诱导出的电光效应,系统地研究大气环境下热极化条件(极化温度、极化时间、极化电压)对电光效应的影响。实验结果表明:在最佳极化条件下(406℃、20 min、-2.4 kV),波导内的电光系数为(rTM=0.059±0.001 pm/V,rTE=0.053±0.001 pm/V),且光波导结构中还存在一个较低的极化阈值电压(100 V);实验还发现采用负极化诱导方式产生的电光系数较正极化提高15%左右。     

聚合物偶极子天线型光纤电场传感器

设计并初步成功制作了聚合物光纤电场传感器.假设聚合物材料的电光系数r13=10 pm/V,设计的两种电场传感器的半波电场Eπ=36.2和15.8 kV/m.用自制的二阶非线性光学聚合物BPAN-NT作为聚合物光纤电场传感器的芯层材料,制作了电光调制器.用反应离子刻蚀的方法制作脊形光波导,通过电晕极化使芯层具有电光效应,...     

非线性有机物和聚合物在波导光互连中的应用研究

硅基底波导光互连技术具有可以充分利用成熟的半导体工艺,与VLSI电子器件工艺 相容好等特点,引起了人们极大的研究兴趣。近几年飞速发展的非线性有机物和聚合物因它们同无机材料相比具有潜在优越的光学和结构特性,用于波导光互连更显示出良好的发展前景。首先它们用于开关结构的设计,为波导光互连器件的动态控制提供了又一可能性,它涉及新工艺和理论两方面研究。其次有些有机物和聚合物的电光系数与铌酸锂的相当,有的甚至高出许多,它们在连续沉积薄膜时,其电光效应无明显的改变,制作的电光调制     

热光效应的微流体光波导结构分析

提出了一种基于微流控芯片由热光效应引起的微流体光波导结构。光波导芯层及覆层材料均为微通道中同种不同温度的液体。在微通道的上下面分别设计金属铜电极,在电极两端施加电压,对通道内液体加热。通过液体热传导,使得接近沟道壁边缘层与沟道中间层之间产生由高到低的温度分布。根据液体热光效应,液体在不同温度下折射率不同,沿着通道壁边缘层到通道中间层之间折射率由低到高,实现折射率渐变型平面光波导。电极两端所施加的电压大小及加热时间长短控制微沟道内温度高低,温度的高低决定了液体折射率分布,从而调节光波导实现单/多模传输。这种可调谐光波导结构可望在微流控光学器件中得到应用。     

硅基光波导及光波导开关的研究进展

ＳｉＯ２ 光波导、重掺杂光波导、ＳＯＩ光波导、合金光波导及聚合物光波导等低损耗硅基光波导的研究已取得了很大的进展,随着这些波导的硅基光开关不断研制出来,各种光开关结构也不断提出来了。为了解决硅的线性电光系数为零的问题,采用了多种方法,以获得强的线性电光效应,实现高速光开关。文章回顾了近十年来硅基光波导及光开关的研究进展。     

基于古斯-汉欣效应的激光束精密平移的研究

为了精密控制激光光束的平行移动,利用双面金属包覆波导结构在导波共振激发时对古斯-汉欣(Goos-Hänchen)位移的增强效应,采用光学非线性晶体材料作为波导的导波层,通过在波导中两层金属膜间加入控制电压,改变波导参量,实现反射光侧向位移的电调谐,得到了720μm范围内的光束平移电控,控制精度可达25nm。结果表明,实验结果和理论模拟吻合较好。预计本工作对光学微加工领域应用具有积极而广泛的意义。     

基于两次衰减全反射结构的激光偏振控制器

为了实现激光偏振态的控制和提高两偏振态消光比,用由各向异性材料加工而成的耦合棱镜并采用两次衰减全反射方法,使具有相同入射角的TE和TM偏振态的共振激发条件不同,即当TE偏振态满足共振激发条件能量耦合进波导时,TM偏振态却不满足共振激发条件而被反射来实现其在空间上的分离.同时将电光系数较大、光学性能和热稳定性好的聚合物材料作为波导层,利用其电光效应来改变共振条件来实现输出光束偏振态的调谐.结果表明,反射型结构插入损耗小于0.2dB,器件的消光比高达27dB,驱动电压为19V.该方案预计在光信息存储、光路由、光开光以及图像处理等光学系统里有着极其广泛的应用.     

聚合物光波导器件的最新进展

由于有机聚合物材料具有介电常数小、电光和热光系数大、热损耗小、易于加工及可垂直集成等优点,聚合物波导器件成为近几年研究的热点。本文在介绍光学聚合物材料优点和一些新型聚合物的基础上,重点讨论了聚合物波导器件的最新进展。     

一种新型的光波导光学相控阵的特性研究

采用光纤作为传输链路,将光子晶体光纤作为系统的输出阵列,LiNbO3波导作为相位调制器,构建了一种基于光纤光路的光波导光学相控阵。根据光学相控阵理论和LiNbO3波导的电光效应,分析了系统的可行性, 并研究了这种新型结构下的光波导光学相控阵的输出衍射特性和光子晶体光纤阵列结构参数的关系。研究结果表明通过控制施加在LiNbO3波导上的电压可以改变出射光束的附加相位从而实现光束的偏转;光子晶体光纤阵列上的纤芯数量、纤芯间距以及纤芯的排列方式等结构参量会对系统的输出光束的光强分布、半峰值全宽度（FWHM）和归一化的振幅分布产生影响。随着光子晶体光纤制作工艺的不断发展,系统的光束扫描质量将会逐渐提高并且色散特性和传输特性将会获得改善,为今后这种光学相控阵系统的设计提供了理论基础和技术依据。     

聚合物光波导器件的最新进展

由于有机聚合物材料具有介电常数小、电光和热光系数大、热损耗小、易于加工及可垂直集成等优点，聚合物波导器件成为近几年研究的热点．本文在介绍光学聚合物材料优点和一些新型聚合物的基础上，重点讨论了聚合物波导器件的最新进展．     

The development of poled polyimide dielectric layers for simultaneous testing and light guiding applications in MCM-Ds

Noninvasive techniques for measuring electric field strengths in multichip module (MCM) substrates can be extremely important in determining ultimate module performance. Certain polymers such as polyimide exhibit an electro-optic response, after appropriate doping and poling, that permits direct measurement of the internal fields with a laser probe. We have built MCM circuit structures using electro-optic polyimides for the dielectric layer. We report thermal, electrical, optical, and electro-optic properties for these dielectric layers. The optical properties of doped and poled polyimides make them attractive for building optical waveguides. We report results for poled polyimide use in both multiple layer structures and optical waveguide formation, and recommend processing guidelines. Further development of doped and poled polyimides may permit optical and electrical interlayers on the same thin-film MCM-D structure.     

Fabrication and characteristics of low loss and single-mode channel waveguides based on DNA-HCTAC biopolymer material

A novel biopolymer, deoxyribonucleic acid-hexadecyltrimethylammonium chloride (DNA-HCTAC), is used as the core layer material in optical waveguide, and the cleanroom technology is successfully applied to fabricate the single-mode channel waveguides with low propagation loss. The prepared DNA-HCTAC material shows high optical quality at the optical telecommunication wavelengths, such as high transparency, relatively high refractive index and low birefringence. In the fabrication approach, polymethyl methacrylate (PMMA) is used as a barrier layer to protect the DNA-HCTAC material from the corrosive of photoresist developer, and the etching conditions are optimized to form the smooth wall and sharp cross-section of the waveguide. Lastly, the optical characteristics of DNA-HCTAC channel waveguides are measured. The results show that the DNA-HCTAC waveguide operates with single-mode propagation and has a low optical loss.     

Loss Measurements on Polymer Thin Film Optical Waveguides

Asimple setup for the measurement of transmission loss in polymer thin film optical waveguides is described.A new electro-optic polymer film has been prepared.The transmission loss of the film is measured before and after corona poling.And the loss is determined to be 1.84 dB/cm and 2.14dB/cm, respectively.     

Sol-gel glass waveguide and grating on silicon

This paper reports on the fabrication and characterization of hybrid organic-inorganic glass sol-gel slab and channel waveguides by ultraviolet light imprinting in thin films deposited by a one-step dip-coating process. The adjustment of chemical composition of the materials provides precise selection of refractive index from 1.48 to 1.52 at the wavelength of 632.8 mn. The refractive index of the waveguides at 1.55 μm is similar to that of optical fiber, thus reducing the reflection loss between the two to less than 0.01 dB. The effect of ultraviolet light exposure and heat treatment on waveguide refractive index is studied. Fabrication parameters to produce ridge waveguides are optimized to achieve very smooth side walls. Propagation losses in these waveguides are ~0.1 dB/cm. Single mode buried waveguides, at 1.55 μm wavelength, with circular mode profile are demonstrated     

Optical intensity modulators using diazo-dye-substituted polymerchannel waveguides

The electrooptic (EO) modulation of 1.32 μm laser light is measured in Mach-Zehnder channel waveguides fabricated with diazo-dye-substituted polymers with coplanar-waveguide (CPW) or microstrip (MS) electrodes. Two types of channel waveguide fabricated by photobleaching or O₂ reactive-ion etching (RIE) exhibit the same EO coefficients r₃₃ under the same poling condition. However, the photobleached waveguides show a lower half-wave voltage than the RIE-fabricated ones because of both the optical power concentration in a core layer and the existence of an EO active cladding layer. These tendencies are well explained by considering “effective” overlap integrals between the optical and electric fields, including the distribution of EO-active regions. The maximum r₃₃ value (26 pm/V) of the poled diazo-dye-substituted polymer is obtained with an RIE-fabricated MS-modulator     

Fabrication of light-induced self-written waveguides with a W-shaped refractive index profile

This paper proposes a novel technique for automatic waveguide formation by means of the self-trapping effect of optical fiber irradiation into a photopolymerizing resin. We investigate experimentally the phenomenon of thin cladding layer formation surrounding the core following the core creation. In the proposed technique, a counterdiffusion effect involving polymerizing monomers via the core/cladding interface causes enrichment of a low refractive index monomer, and a resultant "W-shaped" refractive index profile is realized. The measured propagation loss of the fabricated waveguide is 1.7 dB/cm at 0.68 /spl mu/m wavelength. This technology is appropriate for the fabrication of large-core optical waveguides of greater than 0.5 mm in diameter and is useful for automating the optical fiber connection and packaging process by virtue of being an all-passive optically induced process.     

Mach-Zehnder型有机极化聚合物电光调制器

制备了一种以三层聚合物为波导材料的 Mach- Zehnder型电光调制器 ,其中芯层为新型可交联极化聚胺脂电光功能材料 .主要制备工艺为 :旋涂制备波导薄膜、电晕极化、光刻和氧反应离子刻蚀 .以 1.3μm和 1.5 5μm半导体激光器为光源 ,以光纤耦合输入脊波导调制器 ,从输出端得到很好单模近场图 ,其中从 Y型两分支波导输出的光强基本相同 .同时在示波器中得到清晰的调制信号 .     

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.     

Birefringence control and dispersion characteristics of silicon oxynitride optical waveguides

The design, fabrication and characterisation of birefringent silicon oxynitride planar optical waveguides are described for applications at the wavelength of 1.54 mu m. Form birefringence is attained by interposing a thin silicon nitride film in the waveguide stack, and can be controlled by adjusting the nitride layer thickness. Dispersion characteristics of the oxynitride waveguides have been measured and compared with theory.<>