单端量子点半导体光放大器的动态特性研究
发布时间：2018-07-25 19:25
【摘要】：全光通信是目前光纤通信技术发展的主要方向,其在解决节点间光/电/光转换瓶颈问题的同时也提高了光纤带宽利用率。光信号在光领域处理是全光通信网络发挥优势的基础,而实现全光信息处理又依靠光器件,尤其以半导体光放大器(SOA)为基础的各种功能器件成为光信息处理的关键。SOA可分为体材料Bulk-SOA、量子阱QW-SOA、量子线SOA以及量子点SOA(QD-SOA),其中QD-SOA性能优越,态密度是离散的δ函数,具有高增益、低温度灵敏性、低线宽增强因子及门限电流小等特点。然而双端QD-SOA应用于全光通信网络时,信号经处理后消光比容易退化。单端QD-SOA与双端QD-SOA不同,后端面镀有适当反射率的增透膜,通过双程增益就可以消除光信号消光比退化现象。本文主要对单端QD-SOA在全光信息处理方面应用进行了研究,主要内容有以下几点:1.首先详细讨论了光纤通信的发展历程,对通信网络各基本组成部分(信源、传输媒介及光器件)进行描述,分析了这种通信方式能够解决光/电/光转换瓶颈问题的原因。然后介绍了实现全光波长转换技术和逻辑运算门技术的常规方法,最后阐述了研究单端QD-SOA的目的及意义。2.在讨论传统SOA和双端QD-SOA运转机制和结构基础上,详细介绍了单端QD-SOA的结构特点以及实现光双倍放大原理,另外对有源区量子点材料态密度、制备方法和应用价值进行了相关介绍。3.依据光信号在QD-SOA的传播方程,有源区分段方法,并采用牛顿迭代方法求解载流子的三能级跃迁速率方程,建立了针对研究单端QD-SOA静态特性的理论模型。通过静态模型,分析了单端QD-SOA的静态增益及载流子能级间分布。在有源区粗分段基础上,对每小段再次细化,利用定步长的四阶龙格-库塔法求解非线性跃迁速率方程,最终建立了研究单端QD-SOA动态特性模型。4.构建了基于XGM效应的单端QD-SOA波长转换器方案,通过动态模型研究了转换光增益、啁啾以及消光比特性,分析了输入光功率、有源区长度、最大模式增益、线宽增强因子、能级间载流子跃迁时间、波长转换间隔等对各种特性的影响。并特别对比了单双端QD-SOA波长转换器的消光比特性,得出单端波长转换器结构消光比性能更好。对于基于单端QD-SOA的XGM全光或非门,通过模拟得出改变输入光脉冲序列组合不会影响全光逻辑或非作用效果,另外也证明了降低输入光信号脉宽可以消除超高速光逻辑或非门码型效应的方法。
[Abstract]:All optical communication is the main developing direction of optical fiber communication technology. It not only solves the bottleneck problem of optical / electrical / optical conversion between nodes, but also improves the utilization rate of optical fiber bandwidth. Optical signal processing in optical field is the basis of all-optical communication network, and the realization of all-optical information processing depends on optical devices. In particular, various functional devices based on semiconductor optical amplifier (SOA) become the key of optical information processing. SOAS can be divided into bulk materials, quantum well QW-SOA, quantum wire SOA and quantum dot SOA (QD-SOA), in which QD-SOA has superior performance and density of state is a discrete 未 function. High gain, low temperature sensitivity, low linewidth enhancement factor and low threshold current. However, when two-terminal QD-SOA is used in all-optical communication networks, the extinction ratio is easy to degenerate after signal processing. Unlike QD-SOA with two ends, single end QD-SOA is coated with an antireflection film with appropriate reflectivity, and the degradation of the extinction ratio can be eliminated by double pass gain. In this paper, the application of single ended QD-SOA in all optical information processing is studied. The main contents are as follows: 1: 1. Firstly, the development course of optical fiber communication is discussed in detail, and the basic components of communication network (information source, transmission medium and optical device) are described, and the reason why this communication mode can solve the bottleneck problem of optical / electrical / optical conversion is analyzed. Then it introduces the conventional methods of realizing all optical wavelength conversion technology and logic operation gate technology. Finally, the purpose and significance of studying single terminal QD-SOA are expounded. On the basis of discussing the operation mechanism and structure of traditional SOA and two-terminal QD-SOA, the structure characteristics of single-ended QD-SOA and the principle of optical double magnification are introduced in detail. In addition, the density of states of quantum dots in active region is also discussed. The preparation method and application value were introduced. 3. Based on the propagation equation of optical signal in QD-SOA, the active division method, and the Newton iteration method to solve the three-level transition rate equation of carriers, a theoretical model for studying the static characteristics of single-ended QD-SOA is established. Based on the static model, the static gain and the distribution of carrier energy levels of single-ended QD-SOA are analyzed. On the basis of the coarse segment of the active region, each segment is refined again, and the fourth order Runge-Kutta method with fixed step size is used to solve the nonlinear transition rate equation. Finally, the dynamic characteristic model of single-ended QD-SOA is established. The scheme of single-ended QD-SOA wavelength converter based on XGM effect is constructed. The characteristics of conversion optical gain, chirp and extinction ratio are studied by dynamic model. The input optical power, active region length, maximum mode gain and linewidth enhancement factor are analyzed. The influence of carrier transition time and wavelength conversion interval between energy levels on various characteristics. In particular, the extinction ratio of single-ended QD-SOA wavelength converters is compared, and the performance of single-ended QD-SOA wavelength converters is better than that of single-ended QD-SOA wavelength converters. For XGM all-optical or non-gate based on single-ended QD-SOA, the simulation results show that changing the combination of input optical pulse sequences will not affect the all-optical logic or non-effect. It is also proved that reducing the pulse width of the input optical signal can eliminate the ultra-high speed optical logic or non-gate pattern effect.
【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722;TN929.11
本文编号：2144829
[Abstract]:All optical communication is the main developing direction of optical fiber communication technology. It not only solves the bottleneck problem of optical / electrical / optical conversion between nodes, but also improves the utilization rate of optical fiber bandwidth. Optical signal processing in optical field is the basis of all-optical communication network, and the realization of all-optical information processing depends on optical devices. In particular, various functional devices based on semiconductor optical amplifier (SOA) become the key of optical information processing. SOAS can be divided into bulk materials, quantum well QW-SOA, quantum wire SOA and quantum dot SOA (QD-SOA), in which QD-SOA has superior performance and density of state is a discrete 未 function. High gain, low temperature sensitivity, low linewidth enhancement factor and low threshold current. However, when two-terminal QD-SOA is used in all-optical communication networks, the extinction ratio is easy to degenerate after signal processing. Unlike QD-SOA with two ends, single end QD-SOA is coated with an antireflection film with appropriate reflectivity, and the degradation of the extinction ratio can be eliminated by double pass gain. In this paper, the application of single ended QD-SOA in all optical information processing is studied. The main contents are as follows: 1: 1. Firstly, the development course of optical fiber communication is discussed in detail, and the basic components of communication network (information source, transmission medium and optical device) are described, and the reason why this communication mode can solve the bottleneck problem of optical / electrical / optical conversion is analyzed. Then it introduces the conventional methods of realizing all optical wavelength conversion technology and logic operation gate technology. Finally, the purpose and significance of studying single terminal QD-SOA are expounded. On the basis of discussing the operation mechanism and structure of traditional SOA and two-terminal QD-SOA, the structure characteristics of single-ended QD-SOA and the principle of optical double magnification are introduced in detail. In addition, the density of states of quantum dots in active region is also discussed. The preparation method and application value were introduced. 3. Based on the propagation equation of optical signal in QD-SOA, the active division method, and the Newton iteration method to solve the three-level transition rate equation of carriers, a theoretical model for studying the static characteristics of single-ended QD-SOA is established. Based on the static model, the static gain and the distribution of carrier energy levels of single-ended QD-SOA are analyzed. On the basis of the coarse segment of the active region, each segment is refined again, and the fourth order Runge-Kutta method with fixed step size is used to solve the nonlinear transition rate equation. Finally, the dynamic characteristic model of single-ended QD-SOA is established. The scheme of single-ended QD-SOA wavelength converter based on XGM effect is constructed. The characteristics of conversion optical gain, chirp and extinction ratio are studied by dynamic model. The input optical power, active region length, maximum mode gain and linewidth enhancement factor are analyzed. The influence of carrier transition time and wavelength conversion interval between energy levels on various characteristics. In particular, the extinction ratio of single-ended QD-SOA wavelength converters is compared, and the performance of single-ended QD-SOA wavelength converters is better than that of single-ended QD-SOA wavelength converters. For XGM all-optical or non-gate based on single-ended QD-SOA, the simulation results show that changing the combination of input optical pulse sequences will not affect the all-optical logic or non-effect. It is also proved that reducing the pulse width of the input optical signal can eliminate the ultra-high speed optical logic or non-gate pattern effect.
【学位授予单位】：曲阜师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722;TN929.11
【参考文献】
相关期刊论文 前1条
1 张新亮,孙军强,黄德修,易河清;交叉增益型全光波长转换器消光比退化机理[J];华中理工大学学报;1999年10期
相关硕士学位论文 前1条
1 蒋中;半导体光放大器动态特性的研究[D];华中科技大学;2006年
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