As a result , the peak power , pulse width and time delay of the output pulse have been investigated in detail , including the chirp of the input pulse and the linear dispersion of the filter , and some new and important conclusions have been obtained for the first time 并分析了滤波器的线性色散和入射脉冲的啁啾大小对输出脉冲的影响，对实际的光通信系统中器件参量的设计具有一定的指导意义。利用耦合模理论，对几种典型的光纤光栅进行了研究。
At present , signal pulses produced by directly modulated laser diodes have been used in optical fiber communication systems . the experiment reveals that the optical pulses from directly modulated laser diodes are far from gaussian and have near - rectangular temporal profiles with much sharper leading and trailing edges , and then a super - gaussian model , which assumes that an incident optical pulse has a super - gaussian profile , may be more suitable 但在实际的光通信系统中，人们常采用由直接调制半导体激光器产生的光脉冲作为信号脉冲，而实验结果表明这种脉冲具有比高斯脉冲更为陡峭的前沿和后沿，其脉冲形状更接近于超高斯分布，并且通常还带有一定量的啁啾。
In term of the probability of communication system and perturbance theory , the model of the effect of srs to error bit ratio in communication system is established . through the way numerical of simulation , limitations to srs to error bit ration of communication system and input optical power , the number of channel etc are discussed . the obtained conclusion has definitely reference value to the design of practical communication 根据数字通信系统几率的特性和微扰理论，建立了受激喇曼散射对通信系统误码率影响的理论模型，并通过数值模拟讨论了受激喇曼散射对系统误码率、最大输入功率和信道数等的限制，获得了一些对实际光通信系统设计有参考价值的结论。
( c ) propose the scheme to implementing the coder and deoder of optical time - spreading / frequency - hopping , by assigning two orthogonal codes for one user and using these two codes to encoding 1 and 0 respectively , differential detection can be adopted . not only improves system performances in ber , but also resists the interference such as mai , and does n ' t need any control devices to evaluate the optimum decisive threshold 通过给每个用户指定互相关为0的两个地址码分别发送1和0信号以及在接收端采用差分检测技术，避免了ook (开关键控)光通信系统中0不发送光脉冲和ook常规检测方式下最佳判决门限必须根椐用户数等外界环境而改变，从而提高了系统性能和降低了系统的复杂度。
The coupling issues with optical fibers are often deal with in many application fields of high - power ld , such as the light sources and pumping sources of optical fiber amplifiers in optical fiber communications systems , laser surgery operation in medicine , laser welding and heat processing in materials mechanical process and so on 大功率ld的许多应用领域和应用场合都涉及到与光纤的耦合,比如光通信系统中的光源和光纤放大器的泵浦源,医疗方面的激光手术,材料加工方面的焊接和热处理等等。
Being key components of optical fiber communication , fabry - perot filters and fiber grating filters have been applied in optical sources , wdm multiplexing and de - multiplexing , and add - drop multiplexing , wavelength routers , optical switching of all optical network etc . , which greatly promote the advance of high . speed optical communication technology 而法布里-珀罗滤波器和光纤光栅滤波器是现代光通信系统中的关键器件，它被广泛应用于光纤通信的各个关键环节，从光源、波分复用的分波和合波，到全光网络的上下路、波长路由；光交换等。
Iron - doped photorefractive lithium - niobate crystals ( linbo3 : fe ) have good electro - optic , acoustic - optic , nonlinear characterizations , and hardly light absorption and photorefractive sensitivity in the wavelength around 1550nm , which makes them attractive for using as passive optical components in telecommunication networks 而光折变linbo _ 3 : fe晶体具有良好的电光、声光以及非线性特性，且在现有的通信窗口1550nm波长处几乎没有光吸收，对光的敏感性很小，是光折变光栅应用于光通信系统的首选材料。
In this thesis , the principle of polarized light wave transmit in optical fiber is researched , i . e . principle of ternary optical fiber communication is researched . based on the researches , the construction of ternary codes optical end machine and 3b2t optical end machine used in two - state fiber net are designed . the construction and component of circuits in 3b2t optical ( called sign converter circuit - scc ) are designed particularly , including : the clock synchronization module , the data synchronizing , code converting module , frame managing module and error exam and managing module 本文研究了线偏光波动理论以及在光纤中的传输原理，研究了三值光通信系统原理和器件原理；在此基础上，设计了三值光端机和在现有两值光纤网中实现三值光通信的3b2t三值光端机的组成结构，详细设计了3b2t三值光端机的电路组成部分(称为电信号变换电路scc ) ，包括：时钟同步模块、数据同步模块、码元变换模块、帧处理模块及差错检测和处理模块；而且在三值光纤通信基础上，提出了四值光通信的原理和偏分复用的实用化方法。
