摘要:International developing trend for optical fiber communication is presented, including the developing of WDM, TDM, light soliton, SCM and related devices. Also introduced national developing situation of optical communications, especial for National Enginearing Research Centre for Fiber Optical Communication Technology, Wuhan Research Institute of Posts &. Telecommunications M. P. T.
摘要:The physical significance of a squeezed state are given at first. The principle and method of generation of squeezed light soliton are described. At last the detected method of squeezed light is discussed.
摘要:This paper describes the composition of public communication networks at the first, then lays emphasis on the erossconnect matrix and the principle of array switehover for three levels(DACS 1/0, DACS 4/1 and DACS 4/4) of digital access & crossconnect system in the SDH optical fiber network
摘要:An overall description on the problem of SDH network sychronization is given. It reviews the development and evolution of network synchronization of digital network, discusses the necessity for SDH network synchronization from the viewpoint of jitter and wander in the network. The principles of network synchronization on SDH and requiement of ITU-T Rec. G. 81S on SDH clock are also investigated. Then, the hardware structure and operation mechanism of the G. 81S clock are presented. Finally, the G. 81S clock with good performance designed by us is presented.
关键词:SDH netwotk synchronization;G. 81S clock;telecommunications PLL;jitter and wander
摘要:According to the recommendation H. 261 of ITU, the model of video codec and the detailed parameters of video compression coding algorithm are established. On the basis of experiments for simulation in support of software program, the paper represents some valuable conclusions. The results of theory analysis are in accordance with the experimental results very well.
摘要:The mathematics expression of Er3+-doped fiber optimum length from the theoretical model of EDFA are given. According to the expression, we can calculate the optimum length of Er3+-doped fibers by the loss measure. The optimum length is found to be in excellent agree with the result of the experiment. So, we have a very simple, reliable method to decide the optimum length of Er3+-doped fibers.
摘要:The LP-MOCVD epitaxial techniques are applied to study the crystal growth of material InGaAs(P)/InP. With the aids of measure methods, such as X-ray diffraction, photoluminescenee spectrum, α-step and C-V characteristics, the influence of growth processes on material characteristics is analyzed and the optimum growth parameters are obtained. In terms of these parameters, bulk material laser and quantum well laser emitting at 1.31 μm are fabricated with threshold current densities (Jth) 1.1kA/cm2 and 1.0 kA/cm2 respectively. This shows that we have grown high quality InGaAs(P) epitaxial strained layers.