LED照明的光栅光调制器光学特性分析与实验

针对一种新型的光凋制器--光栅光调制器,研究用LED作为其照明光源时对光学调制特性的影响.以部分相干光理论为依据,结合MATLAB仿真,推导出用LED照明光栅光调制器时,光源带宽对成像对比度具有较大的影响,通过滤色片将光源带宽减小到13 nm时,像面上的对比度约为150,进一步减小带宽至10 nm,对比度将达到225.光源的尺寸在与光源到光栅光调制器之间的距离相比小于0.03时,对光栅光调制器的光学信息处理不会有影响,并通过实验加以证实,从而说明采用LED作为光栅光调制器照明光源的可行性.     

基于双缝隙结构的电光调制器设计与工艺实现

受铜线带宽小、延时大、功耗高的限制,下一代芯片互连较为可行的一种解决方式是采用光互连.调制器作为其中的关键器件,有重要的研究意义.设计了一种新型的硅基双缝隙波导电光调制器,该调制器结构采用法布里-珀罗微谐振器,依靠缝隙内高非线性聚合物的快速电光效应,通过外加电压达到调制效果.调制器结构包含了新型的一般微纳波导到双缝隙波...     

基于有限元法的新结构LiNbO3电光调制器的分析与优化

对传统结构的LiNbO3电光调制器进行了改进,并用有限元法对改进后的电光调制器进行了分析计算,采用T形电极、脊波导和空气背槽的新型LiNbO3电光调制器在进行了结构尺寸优化后,相速完全匹配,带宽可达98 GHz,特性阻抗为52 Ω,损耗系数为0.464 dB/(cm·GHz1/2),半波电压为7.13 V,其性能远优于传统结构的调制器.     

InP基矩形马赫-曾德高速电光调制器行波电极设计与测试

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.     

超高速行波电吸收调制器的k值设计方法

介绍了一种用于超高速行波电吸收调制器(TW-EAM)设计的“k值带宽法”.该方法考虑了影响调制器带宽的阻抗失配、相速度失配、微波衰减等因素,说明一个优化设计的TW-EAM其带宽可达到140 GHz.     

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采用对比分析的方法,对基于TM703FB四极管调制技术的高压调制器和基于IGBT串联技术的全固态调制器的工作原理以及实验结果进行了对比分析。对比分析表明,采用IGBT串联技术的新型全固态高压调制器相对采用电子管技术的传统高压调制器具有众多优点,在HL-2A物理实验中具有重要的应用价值。     

新型结构超宽带LiNbO3电光调制器的优化设计

采用有限元软件对新型结构的铌酸锂电光调制器进行了优化设计.分析表明,采用脊波导和T型电极相结合的方式,能在保持高的特征阻抗的同时有效的实现相速匹配和有效降低电极损耗,从而较好的提高器件性能,是一种比较有潜力的调制器.利用优化结果,给出一种带宽达153 GHz,半波电压为8.55 V,特征阻抗为44 Ω的调制器的设计例子.     

SOI环形光波导谐振腔双层石墨烯调制器

在片上光互连系统中,电光调制器起到将电信号调制为光信号的作用,是光互联系统中的核心部件之一。调制器的3 dB带宽决定着载波所能携带的最大信息量,是衡量调制器性能的核心参数。利用石墨烯和高Q环形谐振腔设计成具有CMOS结构的新型调制器,其集成了石墨烯的宽带吸收、载流子迁移率高等材料优势和高Q值环形光学谐振腔的光程放大的结构优势,通过理论计算,其3 dB调制带宽可以达到100 GHz。同时,基于微环谐振腔的石墨烯电光调制器结构可以方便的与光互联系统中的波分复用器相集成,从而提升片上光互联系统的集成度和降低技术复杂性。     

SOI环形光波导谐振腔双层石墨烯调制器（英文）

在片上光互连系统中,电光调制器起到将电信号调制为光信号的作用,是光互联系统中的核心部件之一。调制器的3dB带宽决定着载波所能携带的最大信息量,是衡量调制器性能的核心参数。利用石墨烯和高Q环形谐振腔设计成具有CMOS结构的新型调制器,其集成了石墨烯的宽带吸收、载流子迁移率高等材料优势和高Q值环形光学谐振腔的光程放大的结构优势,通过理论计算,其3dB调制带宽可以达到100GHz。同时,基于微环谐振腔的石墨烯电光调制器结构可以方便的与光互联系统中的波分复用器相集成,从而提升片上光互联系统的集成度和降低技术复杂性。     

基于VO2薄膜相变原理的温控太赫兹超材料调制器

利用二氧化钒薄膜绝缘相–金属相的相变特性, 提出了一种基于超材料的温控太赫兹调制器, 研究了相变超材料在太赫兹波段的传输特性和温控可调谐特性. 当入射太赫兹波为水平偏振或垂直偏振状态时, 器件的透过率谱线在1 THz附近呈现出两个独立的、中心频率分别为1.3 THz和1.7 THz、 带宽分别为0.2 THz和0.35 THz的 透射宽带. 当温度从40℃至80℃变化时, 两宽带的透过率发生明显的降低, 在二氧化钒的相变温度(68℃)时尤其灵敏, 对入射光的二种偏振状态, 调制深度均达到60%以上, 实现了良好的调制效果. 关键词： 太赫兹超材料 2薄膜')" href="#">VO₂薄膜 调制器 相变     

Ultrabroad-bandwidth electro-optic modulator based on a cascaded Bragg grating

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.     

Characteristic of a broadband Ti:LiNbO3 optical modulator with buried electrodes and etched grooves in the buffer layer

Traveling wave Ti:LiNbO₃ Mach-Zehnder optical modulators with buried electrodes and etched grooves in the SiO₂ buffer layer are analyzed by the finite element method. The tradeoff between the bandwidth BW and the half-wave voltage Vπ is discussed. The value of BW/Vπ is used to weight the total performance of the modulator. Taking a thick buffer layer and etching deep grooves in the buffer layer are demonstrated as two effective methods to improve the performance of the modulator. A 3-dB optical bandwidth of 18 GHz with half-wave voltage 5V at a wavelength of 1.55 pm could be obtained even though the electrode is not very thick. When the requirement of half-wave voltage is not very critical, a bandwidth of more than 100 GHz can be obtained.     

The effect of conductor loss on half-wave voltage and modulation bandwidth of electro-optic modulators

In this paper, we theoretically deduce the expressions of half-wave voltage and 3-dB modulation bandwidth in which conductor loss is taken into account. The results suggest that it will affect the theoretical values of half-wave voltage and bandwidth as well as the optimized electrode's dimension whether considering the conductor loss or not. As an example, we present a Mach-Zehnder (MZ) type polymer waveguide amplitude modulator. The half-wave voltage increases by 1 V and the 3-dB bandwidth decreases by 30% when the conductor loss is taken into account. Besides, the effects of impedance mismatching and velocity mismatching between microwave and light wave on the half-wave voltage, and 3-dB bandwidth are discussed.     

基于双音外差的电光相位调制器半波电压自校准测量方法

电光相位调制器是光纤通信系统、微波光子系统和相干光通信系统中的关键器件之一. 作为器件本征参数, 电光相位调制器的半波电压通常利用光谱方法和电谱方法进行测量. 光谱方法受到光源线宽和光谱仪分辨率限制, 测量的分辨率较低; 电谱方法则需要光电检测之前将相位调制转换成强度调制, 电谱方法的主要困难在于需要对探测器的不平坦响应进行额外校准. 提出了利用双音外差实现电光相位调制器半波电压自校准测量新方法, 该方法利用双音电光相位调制的边带与移频光载波的外差拍频, 对外差拍频信号进行频谱分析, 获得电光相位调制器的半波电压; 通过设定双音调制信号的频率关系, 克服了探测器光电转换中的不平坦频率响应, 实现了自校准测量. 该方法可扩展探测器和频谱仪的测试频率两倍以上, 节省至少一半的带宽需求. 与光谱测量方法相比, 该方法测试分辨率大幅提高且避免了光源线宽的影响; 与传统电域测量方法相比, 该方法无须额外校准, 无驱动功率和工作波长限制, 且对测试仪器带宽需求降低一半以上. 实验证实了所提方法获得的电光相位调制器半波电压的测量结果与光谱分析法获得的结果一致, 且大幅度地提高了测量范围和分辨率. 该方法提供了非常简单的电光相位调制器微波特性化分析方法, 对其他光电子器件分析也提供了参考.     

Measurement of modulation index and half-wave voltage of an electro-optical phase modulator with a dispersion-based phase filter

In this paper, a novel method based on the use of an optical phase filter is proposed to evaluate the modulation index, as well as the half-wave voltage of an optical phase modulator. When a phase modulated signal propagates along the length of a dispersive fiber, the fiber dispersion acts as an optical phase filter and spectrally alters the relative phasing of the phase modulated signal, causing the phase modulation to become intensity modulation, which allows the swept frequency measurement of phase modulators by using a vector network analyzer. The modulation index and half-wave voltage as a function of the modulation frequency are experimentally measured for a commercial phase modulator, which agree well with the results obtained using the widely accepted optical spectrum analysis method. The proposed method requires only a length of dispersive fiber and works without any small-signal approximation, which is applicable for different driving levels and operating wavelengths with the same setup.     

Design and analysis of coplanar waveguide optical modulator using finite element method

An analysis is given on the finite element method (FEM) for calculating the various parameters of optical modulators and a computer program is written to solve the finite element equation. Based on this method, a Mach-Zehnder type electro-optic modulator with coplanar waveguide (CPW) electrode is designed and fabricated. When compared with the Fourier series method, small differences on the 3-dB bandwidth, characteristic impedance and half-wave voltage, etc. are obtained.     

Electro-optical modulator using SiO2 waveguides with thermal poling on a Si substrate

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.     

一种基于确定性量子密钥分发误码判据的相位调制器半波电压的精确测定方法

基于相位编码的量子密钥分发系统需要对信息加载的相位调制器的半波电压进行精确的测定以减小量子密钥的误码率,相位调制器半波电压的测量精度直接影响到了量子密钥分发系统的最终误码.本文提出了一种基于确定性量子密钥分发误码率判据的相位调制器半波电压的精确测定方法,所采用相位调制器的半波电压的测量精度达到了2mV,实验结果表明这种方法可以用于量子密钥分发实际应用系统中实时获得不同条件下的行波相位调制器的半波电压以最大程度地减小由于相位信息不准确加载而带来的系统误码.     

500 MHz LiNbO3 2×2光开关/调制器

本文描述一种采用铬-金电极的Ti:LiN_bO₃型2×2光开关/调制器。给出了该器件的设计参数,工艺条件,带单模尾纤的器件性能为:总插入损耗<8dB,开关电压<10V,串音<-15dB(λ=1.3μm)。本文讨论了器件的高频特性,测得器件的调制频率>500MHz。     

Optimizing Design for the Traveling Wave Electrodes in Low-Drive High-Speed Electro-Optic Polymer Modulators

Electro-optic (EO) polymer modulators are very promising in the realization of cost-effective and high-performance optical transmissions. In this article, general strategies and specific designs of the traveling wave electrodes in EO polymer modulators were presented to reduce the modulator drive power while maintaining a broadband response. The optimum device parameters and corresponding conditions were estimated using finite element method based on electrode design. In calculating the results, the comprehensive characteristics of polymer modulator with 1.21 V half-wave voltage and 91 GHz bandwidth was demonstrated with electro-optic interaction length is 20 mm, electro-optic coefficient is 55 pm/V, and operation wavelength is 1.319 μm. These results agree with the 0.8 V half-wave voltage and 30 mm electro-optic interaction length reported in Science. In the five designs presented, a hybrid electrode structure combining CPW and microstrip lines were advanced. The characteristics of this structure are like that of microstrip lines with a single-arm electrode on one arm of the waveguide, but it solves the problem of microstrip to coaxial line transition and corona polarization.