Fiber Raman Amplifier And Its Applied Research In High-speed Optical Fiber Communication Systems

The optical fiber communication systems are developed into high-speed,wide-band and long-distance optical fiber communication systems with huge capacity. As the most widely used method in the backbone communication networks,dense wavelength division multiplexing technology has made remarkable progress. The enhancement of the transmission speed leads to the increase of the input power,at the same time the transmission with huge capacity needs the further reduction of the channel separation in the existing communication windows. All of this makes nonlinear effects which has been ignored in the low-bit rate linear systems distinguished,which brings forward the new request of optical fiber amplifiers. The future amplifiers must be the distributing amplifiers,which have not only flat gain but also wide-band and the characteristic of the arbitrary band amplification. As far as it goes,fiber Raman amplifiers are the sole amplifier which can be competent. More and more people pay attention to fiber Raman amplifier and research on it. This work studies not only the design method and characteristics of fiber Raman amplifiers and hybrid fiber amplifiers which are composed of fiber Raman amplifiers and Erbium-doped fiber amplifiers but also the influence of fiber Raman amplifiers and hybrid fiber amplifiers on wavelength division multiplexing systems,on the base of the theory of fiber Raman amplifiers and VPITransmissionmaker simulation platform.In chapter 2,the theory of fiber Raman amplifiers is introduced firstly. On the base of it,the theory model of fiber Raman amplifiers including power analysis model and field analysis model is based. Then the Raman gain spectrum,the fiber loss spectrum and the fiber dispersion spectrum which will be used in the future research are simulated. Finally some photonic design automation simulation software and the simulation platform mainly used in this work——VPITranmissionmaker are introduced. In chapter 3,the influence of two kinds of fiber Raman amplifiers on a single 40Gb/s system is studied and the optimal designs of each system are given.The fast design method of broadband fiber Raman amplifiers is introduced in chapter 4. Using the method,the gain-controlled broadband fiber Raman amplifiers in arbitrary band can be designed quickly. After the characteristics of broadband fiber Raman amplifiers are studied,some useful conclusions on the mutual effects between pumps and signals,pumps and pumps,signals and signals are deduced. The noise characteristics of broadband fiber Raman amplifiers are also studied. Finally after wavelength division multiplexing optical fiber transmission system based on fiber Raman amplifiers is studied in detail,the influences of the collocation of dispersion compensation fiber,the dispersion coefficient,dispersion slope,effective core area,nonlinear index,Rayleigh backscattering coefficient,length of fiber Raman amplifiers,launch power and the bandwidth of Bessel filter on BER are deduced. The influence of Rayleigh backscattering noise on BER and OSNR is also studied in detail,which affects the performance of long haul transmission badly.In chapter 5,a design method of hybrid fiber amplifiers is introduced firstly. Then a broadband hybrid fiber amplifier is designed. The gain and noise characteristics of it are studied. Finally an effective method to restrain noise is put forward. After the method is applied in wavelength division multiplexing high-speed optical fiber communication systems,on the base of VPITranmissionmaker,the influences of the dispersion coefficient,dispersion slope,effective core area,nonlinear index,length of fiber Raman amplifiers,launch power, the bandwidth of Bessel filter and the mark probability in Non-Return-Zero code on BER are studied.We have widely studied the design,the characteristics and the influences of fiber Raman amplifiers and hybrid fiber amplifiers on wavelength division multiplexing high-speed optical fiber communication systems,combining theory analysis with numerical simulation in the dissertation. The...