直调分布反馈激光器的调制特性研究与优化

发布时间：2018-02-17 05:23

本文关键词： 直接调制激光器电吸收调制激光器调制带宽频率啁啾　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：直调激光器(DML)是一种低成本的光发射器件,广泛应用于光纤接入网和数据通信网中。近些年由于接入网和数据通信业务的蓬勃发展以及用产量多的特点使得中短距离的通信对光发射器件的需求巨大。在中短距离通信中常用的光发射器件除了DML还有电吸收调制激光器(EML)。然而在中短距离传输上还要求器件成本低、功耗及尺寸小,DML由于结构简单更具优势,但DML受带宽和啁啾的限制一般只应用于10Gb/s以下及短距离的接入网,然而近10年有了较大的发展,在更高速率和20km以下短距离传输方面有着与EML相比拟的性能。本课题基于物理分析模型,通过数值仿真研究影响DML调制带宽和啁啾特性的因素,并优化DML的调制特性,即一方面提高调制带宽,另一方面减小啁啾,同时在系统传输下将优化后的DML与EML做对比,为实际系统搭建时光发射器件的选取提供方案参考。本论文的主要创新与成果包括以下几个部分:(1)建立了一整套从材料特性到器件特性研究的仿真分析工具,包括描述光场的一维行波模型、材料增益计算的自由载流子模型以及材料激子吸收计算的库仑模型,并与文献结果对比验证工具的可靠性。(2)从材料、结构上全面优化了DML的带宽和啁啾,包括微分增益、线宽展宽因子、非线性增益饱和因子、耦合强度等;利用开关电流整形消除弛豫振荡减小啁啾;利用提出的局域双模模型优化推挽调制的分布反馈激光器获得了60GHz的调制带宽等;(3)优化后的1.5μm波段DML在10Gb/s、25Gb/s、40Gb/s速率下能传输EML一半的距离,值得一提的是10Gb/s调制时,在20km以内都可采用DML来降低网络成本;采用开关整形和推挽调制技术可将DML传输能力提高一倍。
[Abstract]:The direct-modulated laser (DML) is a low-cost optical emitter. It is widely used in optical fiber access network and data communication network. Due to the rapid development of access network and data communication service and the characteristics of high output in recent years, there is a huge demand for optical transmitter devices in medium and short distance communication. In short range communication, the common optical emission devices besides DML are electrically absorbed modulation lasers (EMLs). However, in short and medium distance transmission, the cost of the devices is also required to be low. Because of its simple structure, power consumption and small size DML are more advantageous. However, DML is limited by bandwidth and chirp, but it is only used in access networks of less than 10 GB / s and short distance. However, it has developed greatly in the last 10 years. In the aspect of higher speed and shorter distance transmission below 20km, the performance of DML is comparable to that of EML. Based on the physical analysis model, the factors affecting the modulation bandwidth and chirp characteristics of DML are studied by numerical simulation, and the modulation characteristics of DML are optimized. On the one hand, the modulation bandwidth is increased, on the other hand, the chirp is reduced. At the same time, the optimized DML is compared with the EML under the system transmission. The main innovations and achievements of this paper include the following parts: 1) A set of simulation analysis tools from material characteristics to device characteristics are established. Including the one-dimensional traveling wave model describing the light field, the free carrier model for calculating the material gain and the Coulomb model for calculating the exciton absorption of the material, and comparing with the results in the literature to verify the reliability of the tool. The bandwidth and chirp of DML are optimized, including differential gain, linewidth broadening factor, nonlinear gain saturation factor, coupling intensity, etc. Using the proposed local two-mode model to optimize the push-pull modulation distributed feedback laser, the modulation bandwidth of 60GHz has been obtained.) the optimized 1.5 渭 m band DML can transmit half of the EML at the rate of 10Gb / s / s 25Gb / s and 40Gb / s. It is worth mentioning that when the modulation is 10Gb / s, it is worth mentioning. DML can be used to reduce network cost within 20km, and switching shaping and push-pull modulation techniques can double the transmission capacity of DML.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248

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