A novel method based on a map of noise figure and gain is proposed to analyze efficiently the dependence of the noise figure and gain for edfas on the edf length and the pump power . the characteristics of various edfas are studied and compared . secondly , some important parameters are introduced to describe the characteristics of edfas 文中从理论上系统分析设计了结构参数对各种edfa性能的影响，最后通过实验验证；第四，针对波分复用系统要求edfa必须具备增益锁定功能，提出采用单根光纤光栅的方法来箝制l - bandedfa的增益。
The forming mechanism of crosstalks in the tdm system was analyzed theoretically , and the relationship between crosstalks and the extinction ratio of optical pulse modulator used in the tdm system was investigated . the interchannel and intrachannel crosstalks in the wdm system were discussed separately , and the contributions to crosstalks were appraised from architecture ’ s alteration , the finite isolation between channels in multiplexers or demultiplexers , and nonlinear effects in the system . noises in the large - scale multiplexing system were studied theoretically , and all kinds of factors were considered that have relation to noises , phase resolution , and dynamic range of the system , such as multiplexing channel number , the length of the transmission fiber , using in - line erbium - dropped fiber amplifiers or not , and so on 本文从理论上分析了光纤水听器时分复用系统串扰的形成机理,分析了光脉冲调制器的消光比与系统串扰的关系;分别对光纤水听器波分复用系统的异频串扰和同频串扰进行了理论分析,研究了光纤水听器波分复用结构、波分复用器与解复用器隔离度等因素以及非线性效应对系统串扰的影响;对大规模光纤水听器复用系统噪声进行深入细致的理论分析,研究了系统噪声、相位分辨率、动态范围与复用数目、传输光纤长度、中继光纤放大器等诸多因素的关系。
Moreover , compensated for aberration of ball lens by designing phase compensating plate to get a higher energy utilization rate . third , combining with the light beam property of dwdm system , put forward taking fresnel lens array as fiber arrayed collimator , designed differently structured lens array and discovered the arrayed collimator loss property , which compared with the existing parameter of fiber collimator , embodies many advantages as arrayed collimator 结合密集波分复用系统的光束耦合特点，提出用菲涅尔透镜列阵做光纤阵列准直器，并设计不同结构的透镜列阵，得出了该阵列准直器的光束耦合损耗特征，与现有的光纤准直器的参数相比，体现出用菲涅尔透镜列阵作阵列光纤准直器的诸多优势。
