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对基于行波电极的硅-有机复合集成电光调制器进行研究,构建调制器的波导电极结构模型,分析特征阻抗和微波有效折射率对调制器频率响应的影响。通过对电极结构的仿真优化,完成调制器芯片的设计与制备,研究电光聚合物材料的片上极化工艺,得到高性能硅-有机复合集成电光调制器。对研制调制器电极的电学S(Scatter)参数进行测试,分析得到的电极特征阻抗和有效折射率与仿真设计结果基本相符。测试得到电光调制器的3 dB带宽大于50 GHz。 相似文献
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基于Wheeler变换模型,提出了一种分析多层介质微波特征参数的方法--Wheeler's Conforming Mapping扩展变换法,并利用该方法得到了微波特征参数与各层介质参数之间的表达式,在此基础上分析了微带电极的微波特性参数. 与准静态有限元法(QS-FEM)相比,Wheeler's Conforming Mapping扩展变换法不仅计算准确而且具有更高的计算效率. 将该方法应用于聚合物电光调制器的特性研究,对传统模型进行改进,通过添加补偿层来调整微波等效折射率和特征阻抗,改善微波与光波有效折射率的失配度,在理论上实现了聚合物电光调制器的速率和阻抗的同时匹配.
关键词:
Wheeler扩展变换法
微带电极
特征参数
等效介电常数 相似文献
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提出了一种由新型沟槽耦合器和90°弯曲波导构成的InGaAsP/InP基矩形马赫-曾德电光调制器,对该调制器的L型波导相移臂设计了T型类微带行波电极.首先利用电极的等效电路估算带宽上限,进而在考虑阻抗匹配、回波损耗以及带宽等性能的基础上,使用有限元方法对电极的传输、输入/输出以及过渡区的结构参量进行优化.仿真结果表明由于受到电极输入及过渡区的性能限制,设计的整体行波电极匹配阻抗大于42Ω,回波损耗小于-15dB,带宽可达65GHz.测试制备的Ti/Au行波电极,得到回波损耗为-12dB和带宽为20GHz的最优性能. 相似文献
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本文描述了一种数值分析方法,计算了集成光学中电光器件电极的电场分布。在电极无限薄的假设条件下,把数值分析法计算的结果同保角变换法的结果进行了比较,并讨论了电极厚度和缓冲层对电场以及特征参量的影响。计算结果表明电极厚度对电场分布影响较小,但特征阻抗和有效介电常数随电极厚度增加明显减小。而且使用缓冲层使波导的有效深度增加,电场强度减小,特征阻抗和有效介电常数都发生很大变化。利用这些特性可对集成光学电光器件的电极进行优化设计。 相似文献
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电化学阴极沉积制备氧化镍/碳纳米管复合电极的准电容特性 总被引:4,自引:0,他引:4
采用催化裂解的方法制备了碳纳米管,其比容量为12F/g.采用碳纳米管作为电极基体,采用阴极电化学还原Ni(NO3)2的方法在碳纳米管基体表面均匀的沉积了纳米氧化镍颗粒并由此制备了氧化镍碳纳米管复合电极材料.采用循环伏安、恒流充放电、交流阻抗及扫描电镜等方法考察了复合电极材料的容量特性、阻抗特性、自放电特性以及电极表观特征.实验表明复合电极具有良好的电化学特性,碳纳米管基体在明显降低氧化镍材料的阻抗的同时还提高了电极材料的电化学容量并拓宽了电极材料的有效工作电位窗,复合电极在6mol/LKOH电解液中比容量达到25F/g且表现了良好的电化学可逆性.与碳纳米管基电容器相比,采用氧化镍复合电极材料组装的电容器具有较低的自放电率. 相似文献
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采用电化学阴极沉积还原Co(NO3)2的方法制备了具有准电容特性的氧化钴电极材料,其比容量达到280 F/g,采用CNTs作为电极基体,在其表面均匀的沉积了纳米钴化镍颗粒并由此制备了氧化钴碳纳米管复合电极材料.采用循环伏安,恒流充放电,交流阻抗及扫描电镜等方法考察了复合电极材料的容量特性、阻抗特性、自放电特性以及电极表观特征.实验表明复合电极具有良好的电化学特性,CNTs基体在明显降低氧化镍材料的阻抗的同时还提高了电极材料的电化学容量并拓宽了电极材料的有效工作电位窗,复合电极在1 mol/L KOH电解液中比容量达到322 F/g且表现了良好的电化学可逆性.并分别采用氧化钴/CNTs复合电极作为正极,活性炭纤维作为负极制备了复合型电化学电容器,其工作电压达到1.4 V,电容器质量比容量达到47 F/g.在0.1 A/cm2放电时,复合型电容器的能量密度达到10 Wh/kg,兼具高能量特性和优良的大电流放电特性. 相似文献
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1 IntroductionFOr LiNbO3 modulators, the bandwidth is mainly restricted by the microwaveattenuation of the travelling--wave electrode and the phase velocity ndsmatch betWeenmicrowave and optical wave in the devices. When the phase velocity matching issatisfied it is very i~rtant to decrease the microwave attenuation for expandingbandwidth. The thecrowave propagating lOSS is the main source Of the microwaveattenuation in the interactive region. The larger the cross-sectional area or the lOn… 相似文献
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The characteristics of Z- cut LiNbO3 optical modulators with novel complex electrode are discussed by using the finite element method (FEM) and studied experimentally in this paper. The travelling wave electrode consists of upper and lower parts. It can easily realize phase velocity matching between microwave and optical wave and drastically reduce microwave electrode loss. An electrooptic modulator with larger than 100 GHz bandwidth and half wave voltage 6 V is designed, fabricated and measured. Vπ is 5.1 V and the attenuation coefficient a0 is 0.3 dB/(cm· GHz1/2 ). The experimental results show that the modulator has great potentiality for expanding bandwidth. 相似文献
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These experiments examine how comodulation masking release (CMR) varies with masker bandwidth, modulator bandwidth, and signal duration. In experiment 1, thresholds were measured for a 400-ms, 2000-Hz signal masked by continuous noise varying in bandwidth from 50-3200 Hz in 1-oct steps. In one condition, using random noise maskers, thresholds increased with increasing bandwidth up to 400 Hz and then remained approximately constant. In another set of conditions, the masker was multiplied (amplitude modulated) by a low-pass noise (bandwidth varied from 12.5-400 Hz in 1-oct steps). This produced correlated envelope fluctuations across frequency. Thresholds were generally lower than for random noise maskers with the same bandwidth. For maskers less than one critical band wide, the release from masking was largest (about 5 dB) for maskers with low rates of modulation (12.5-Hz-wide low-pass modulator). It is argued that this release from masking is not a "true" CMR but results from a within-channel cue. For broadband maskers (greater than 400 Hz), the release from masking increased with increasing masker bandwidth and decreasing modulator bandwidth, reaching an asymptote of 12 dB for a masker bandwidth of 800 Hz and a modulator bandwidth of 50 Hz. Most of this release from masking can be attributed to a CMR. In experiment 2, the modulator bandwidth was fixed at 12.5 Hz and the signal duration was varied. For masker bandwidths greater than 400 Hz, the CMR decreased from 12 to 5 dB as the signal duration was decreased from 400 to 25 ms.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Jiu-sheng Li 《Optik》2008,119(1):19-22
A novel optical modulator using SiO2 waveguides on a silicon substrate is proposed. The modulator is analyzed and designed with the finite element method. The numerical results have shown that an optimally designed modulator can give a broad bandwidth, good impedance match, and low cost. The proposed modulator can be fabricated easily using Si-based very large-scale integrated technology, and it is very suitable for opto-electronic integrated circuits. 相似文献
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提出一种新型基于Si2N2O基体的LiNbO3行波调制器,利用有限元方法对该调制器进行数值分析并获得调制器的优化结构尺寸.该新型调制器带宽达到120 GHz,半波电压为3.5 V,特性阻抗为50.2 Ω.结果表明该调制器具有大的调制带宽和良好的阻抗匹配,在未来光通信中具有很好的应用前景. 相似文献
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It is shown that the bandwidth of a traveling-wave electro-optical modulator can be greatly increased by matching of the group velocities of the optical and rf waves in the waveguides with cascaded Bragg gratings. A LiNbO>(3) Mach-Zehnder modulator with 1-V half-wave voltage and a bandwidth in excess of 100 GHz is proposed and its performance evaluated. 相似文献
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A compact optical microfiber phase modulator with MHz bandwidth is presented. A micrometer-diameter microfiber is wound on a millimeter-diameter piezoelectric ceramic rod with two electrodes. When a voltage is applied to the piezoelectric ceramic, the rod is strained, leading to a phase change along the microfiber; because of the small size, the optical microfiber phase modulator can have as high as a few MHz bandwidth response. 相似文献
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Haibo Peng Boyu Wu Qiong Song Fei Lu Shuyun Luo 《International Journal of Infrared and Millimeter Waves》2003,24(9):1587-1596
Hybrid electrode combined coplanar waveguide (CPW) and microstrip lines in ultra-broadband electro-optic modulators. The characteristics of the modulators with hybrid electrode is like that of the modulator with the microstrip lines, in which the microstrip electrode is loaded above only one arm of Mach-Zehnder (M-Z) optical waveguide, besides the problem of microstrip line to coaxial transition and corona polarization in polymer modulators have been best solved at the same time. By using finite element method (FEM), the characteristic parameters such as half-wave voltage, modulation bandwidth characteristic impedance, effective microwave refractive index of polymer modulators with microstrip line and hybrid electrode are analysed and compared in this paper. The results present that velocity match, impendence match and lower microwave propagating loss is easily realized in modulators with hybrid electrode. 相似文献