【作者】 曾丽珠；

【导师】 武星；

【作者基本信息】 天津大学 ， 物理电子学， 2007， 硕士

【摘要】 在国家骨干网长途通信系统中,无电光中继传输已经得到了广泛的应用;而EDFA技术则是长途光通信的核心技术之一。伴随着接入网“光进铜退”时代的来临和用户带宽需求的不断增长,DWDM已经成为长途传输的主要方式。本文就DWDM系统中的EDFA特性为研究对象,主要论述了如下几点:1.全面论述了国内外对EDFA进行增益平坦化的各种方法以及各种方法迄今能实现的水平。2.从理论上分析了EDFA系统的基本原理,阐述了EDFA系统中几个重要的概念,包括增益、噪声系数、增益斜率等;对EDFA的增益与铒纤长度、泵浦功率的关系,噪声系数与铒纤长度、泵浦功率的关系,增益斜率与信号光功率、泵浦光功率的关系数值模拟。3.根据EDFA系统的设计原理,自行设计了一款基于VOA+GFF动态增益平坦的980nm泵浦两级级联EDFA系统。4.采用基于LPG的增益平坦滤波器进行增益平坦实验,实验证明在某些特定条件下能实现±0.1dB的增益不平坦度,但在不同的信号光功率下其输出光的增益斜率不一致;需要进行动态调整。5.提出了基于VOA的增益斜率的调整方法,实验证明该方法的有效性;通过GFF+VOA的增益平坦方法,所设计的EDFA可以在不同的信号光功率、泵浦功率时,始终保持0.1dB的增益平坦特性。更多还原

【Abstract】 Electroless relay transmission is under broad application in the national skeleton long-distance communication system. EDFA has become one of the key techniques in the long-distance optical communication. Along with the age of‘light replacing cuprum’coming and continuous accretion of bandwidth requirement, DWDM has become the primary mode of long-distance transmission. This dissertation is focused on the characteristics of erbium-doped fiber amplifier (EDFA) used in dense wavelength division multiplexing (DWDM), which include:1. All kinds of the methods of gain flattening and the highest level achieved until now of EDFA in the world are expounded overall.2. The fundamental and the basic structure of EDFA system is studied in theory. The key concepts in EDFA system are expounded, including gain, noise figure and gain tilt. The relationships between gain/noise figure and EDF length/pump power, gain tilt and signal power/pump power of EDFA are numerically simulated.3. An EDFA of 980nm pumped, 2-stage cascade based, dynamic gain flattening based on VOA+GFF is designed, according to the design principle of EDFA.4. A gain flatness of±0.1dB within 30nm is achieved through the experiment based on LPG GFF when its output is 15.1dBm,through a mass of experiments. Dynamic gain flattening regulation is needed, because the gain flatness varies with diverse signal power.5. The regulation means of gain tilt based on VOA is put forward; and is proved to be effective. By the means of GFF + VOA, the gain flatness of EDFA system can be maintained at 0.1dB all along with diverse signal power.更多还原