波导调制器的光束传播法设计

以光束传播法分析马赫－陈德尔型波导电光强度调制器的波导宽度，Ｙ型分支角、调制电压等参量与器件特性之间的关系，有利于Ｍ－Ｚ波导电光调制器的优化设计。     

基于扣除法的电吸收调制器本征特性分析方法

基于电吸收调制器的工作原理和等效电路模型对调制器的高频响应特性进行分析,提出了一种采用频率响应扣除法提取有源区本征响应的仿真新方法.该方法能简单地去掉封装网络、夹具及光探测仪器等带来的影响,用该方法得到了待测lnGaAs/InAIAs材料电吸收调制器准确的的高频本征响应特性.     

基于单个和级联电吸收调制器超短光脉冲的产生

为研究电吸收调制器(EAM)产生超短光脉冲的性能,在考虑电吸收调制器频率响应的基础上,通过数值模拟和实验研究的方法,从理论和实验上研究了基于国产单个和级联电吸收调制器的超短光脉冲产生,实验和理论相符.基于单EAM可以产生占空比近12%的短脉冲,级联EAM可产生占空比为8%的短脉冲.     

波导电光调制器结构的全波分析

本文首次用时域有限差分法对波导电光调制器结构进行全波分析。通过引入移动吸收边界条件和自动递归模型,提高了算法的计算精度和效率,获得了调制器结构参数与性能的关系曲线,为实际器件的优化设计提供了重要依据。     

基于有限差分束传播法的Mach-Zehnder型波导电光调制器的模拟设计

针对掺钛铌酸锂Mach-Zehnder型波导电光调制器的结构及折射率分布,运用有限差分束传播方法(FD BPM)进行模拟计算,取得了二维情况下的最佳设计尺寸.在此基础上,把所得的设计结果与原有的用快速傅里叶束传播方法(FFT BPM)所得的结果进行比较和分析.结果显示,运用有限差分束传播方法不仅取得了预期的结果,而且,这种方法比原有的快速傅里叶束传播方法更快捷和方便,是器件设计的理想和现实的数值模拟工具.     

基于电吸收调制器的高速时钟信号的提取

对高速光时分复用系统中(2×10 Gb/s)基于电吸收调制器(EAM)的注入光电混合振荡器的时钟提取方法进行了实验验证. 实验证明,光电混合振荡器必须保证一定的增益才能提取出时钟,在此基础上,无论光电混合振荡器内或外的光功率的增加,将增加提取时钟的幅度,减小提取时钟的时间抖动.当偏置电压一定时,射频幅度增加,则电吸收调制器的窗口变窄,提取时钟幅度增大,抖动减小.     

光电子技术与器件 光调制与器件

TN761 2006065275一种新型谐振腔增强型光调制器结构的研究=A novel resonant cavity enhanced optical modulator structure[刊,中]/周震(北京邮电大学电子工程学院．北京(100876)),马建新…//半导体光电．—2006．27(3)．—250-253提出了一种新型谐振腔增强型(RCE)光调制器结构,它由一个对称型谐振腔增强型光调制器和一个高反镜构成。利用传输矩阵法对该器件的插入损耗及临界吸收厚度进行了模拟分析,并同传统谐振腔增强型光调制器的相关性能进行了比较。分析结果表明,这种结构解决了传统谐振腔增强型光调制器的临界吸收厚度与插入损耗之间相互制约的矛盾,可同时获得低临界吸收厚度和低插入损耗。图5参11(严寒)     

一种利用光电流和光透过曲线测量电吸收调制器插入损耗因素的方法

提出一种新颖的方法用于测量电吸收调制器（electroabsorption modulator,EAM）各种因素造成的插入损耗.此方法仅需要测量波长相关的光电流（I_ph-λ）和光透过功率（P-λ）的数据,通过最小二乘法拟合出结果.理论分析表明此方法较精确,实验表明测试结果与理论拟合结果自洽得很好. 关键词： 电吸收调制器 插入损耗 吸收曲线 光生电流     

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.     

基于有限差分束传播法的Mach-Zehnder型波导电光调制器的模拟设计

针对掺钛铌酸锂ＭａｃｈＺｅｈｎｄｅｒ型波导电光调制器的结构及折射率分布，运用有限差分束传播方法（ＦＤＢＰＭ）进行模拟计算，取得了二维情况下的最佳设计尺寸在此基础上，把所得的设计结果与原有的用快速傅里叶束传播方法（ＦＦＴＢＰＭ）所得的结果进行比较和分析结果显示，运用有限差分束传播方法不仅取得了预期的结果，而且，这种方法比原有的快速傅里叶束传播方法更快捷和方便，是器件设计的理想和现实的数值模拟工具     

具有调制功能的多模干涉型1×3分束器

提出了利用量子约束斯塔克(Stark)效应制作具有调制功能的多模干涉型1×3分束器的设计思想,并详细分析了这种光分束器的工作原理。根据理论计算结果,制作了具有调制功能的多模干涉型1×3分束器。分束器的脊型多模波导长度为275μm,宽度为10μm,波导层采用GaAs/AlGaAs多量子阱结构,厚度约为0.2μm;电极采用共面波导结构。首先用有限差分光束传播法模拟了器件的光波传播特性,然后进行了初步的实验验证。理论模拟和实验结果表明,波长为0.86μm的高斯光束对称入射到多模波导的中心,器件实现了3分束功能;施加3 V的直流偏压,器件的调制深度达90%以上、调制带宽为2 GHz,实现了电吸收调制功能。     

用于光通信的MMI型GaAs光功分器的研制

本文设计了一种能直接与单模光纤阵列相耦合的MMI型光功分器.首先采用导模传输分析法,给出了MMI型光功分器的工作原理,在此基础上完成了MMI型光功分器的设计.最后根据所确定的器件结构参量,用有限差分光束传输法分析了器件结构参量对器件性能的影响.     

Design of novel three port optical gates scheme for the integration of large optical cavity electroabsorption modulators and evanescently-coupled photodiodes

This paper presents a novel scheme to monolithically integrate an evanescently-coupled uni-travelling carrier photodiode with a planar short multimode waveguide structure and a large optical cavity electroabsorption modulator based on a multimode waveguide structure. By simulation, both electroabsorption modulator and photodiode show excellent optical performances. The device can be fabricated with conventional photolithography, reactive ion etching, and chemical wet etching.     

行波电吸收调制器中脊宽对频带宽度的影响

根据行波电吸收调制器（TW-EAM）的微波传输特性,提出了等效电路模型.制作了工作波长为850 nm的GaAs/GaAlAs材料的TW-EAM,并通过等效电路模型分析了特性阻抗Z0、微波传输常数γ和S21,得出脊宽对器件微波特性的影响.从理论上验证了较小脊宽可以降低微波和光波之间的速度失配、波导的传输损耗及传输线和终端及源端之间的阻抗失配.理论模拟得出：脊宽为2 μm时,器件提供的带宽为23.9 GHz.     

Optimization of multiple quantum well electroabsorption modulators

A novel and simple approach for optimization of a multiple quantum well electroabsorption waveguide modulator is presented. In our approach, all four of the modulator characteristic parameters (on-off ratio, insertion loss, bandwidth, and driving voltage) are included. Design examples for GaAs/AlGaAs multiple quantum well modulators are presented. The accuracy of our model is confirmed by comparison between calculated and published experimental data.     

Ultra-short pulse generation for soliton transmission using electroabsorption modulators

A simple and stable technique of optical short pulse generation for soliton transmission based on external modulation is reviewe.By using nonlinearity of absorption characteristics of an electroabsorption modulator, ultra-short optical pulse trains having a shape close to sech² shape can be generated just with sinusoidal modulation, without ultra-short driving pulses and ultra-broad bandwidth of the modulator. The pulse width and the repetition rate can be varied by changing the electrical driving conditions. Quasi-transform-limited optical pulseswith time-bandwidth product of 0.32 were successfully generated by the sinusoidally driven InGaAsP electroabsorption modulator with up to 20 GHz repetition rate. An application of a λ/4-shifted DFB laser-electroabsorption modulator integrated light source to a single-chip soliton source is also described. The high quality of the modulator-generator pulses has been proven by long-distance soliton transmission over 6400 km at 2.5 Gb/s using a recirculating fiber loop.     

Linearization and dispersion tolerable technique for remote access unit in uplink RoF system based on gain-saturated RSOA cascaded EAM

A novel scheme of a remote access unit which is based on an electroabsorption modulator cascaded by a gain-saturated reflective semiconductor optical amplifier is proposed to improve a transmission performance of uplink signal. The cascaded gain-saturated reflective semiconductor optical amplifier plays a role in enhancing linearity of the electroabsorption modulator as well as suppressing dispersion-induced carrier suppression in the uplink transmission using its nonlinear gain property. In the proposed scheme, carrier-to-interference ratio of transmitted 10-GHz band uplink signal was improved by 10.7 dB and the dispersion-induced carrier suppression of 5.65-GHz RF carrier was greatly mitigated by 33.4 dB through the 75.6-km optical link.     

Asymmetrically Apodized Linearly Chirped Fiber Bragg Gratings for Efficient Pulse Compression

Abstract

A simple and stable technique of optical short pulse generation for soliton transmission based on external modulation is reviewe.By using nonlinearity of absorption characteristics of an electroabsorption modulator, ultra-short optical pulse trains having a shape close to sech² shape can be generated just with sinusoidal modulation, without ultra-short driving pulses and ultra-broad bandwidth of the modulator. The pulse width and the repetition rate can be varied by changing the electrical driving conditions. Quasi-transform-limited optical pulseswith time-bandwidth product of 0.32 were successfully generated by the sinusoidally driven InGaAsP electroabsorption modulator with up to 20 GHz repetition rate. An application of a λ/4-shifted DFB laser-electroabsorption modulator integrated light source to a single-chip soliton source is also described. The high quality of the modulator-generator pulses has been proven by long-distance soliton transmission over 6400 km at 2.5 Gb/s using a recirculating fiber loop.     

An optical fiber cable video system

Abstract

A novel and simple approach for optimization of a multiple quantum well electroabsorption waveguide modulator is presented. In our approach, all four of the modulator characteristic parameters (on-off ratio, insertion loss, bandwidth, and driving voltage) are included. Design examples for GaAs/AlGaAs multiple quantum well modulators are presented. The accuracy of our model is confirmed by comparison between calculated and published experimental data.