Study On The Interaction Of Coupled Femtosecond Optical Solitons

Optical soliton communication is an excellent technology,particularly in high-speed communications systems.It can decrease the negative effect of nonlinearity efficiently on system by keeping the balance between dispersion and nonlinearity.In optical soliton communication systems,there are longer relay distance and lower error rate than the normal systems.Modern optical communication systems have developed into higher-speed rate,higher-capacity and longer relay distance.The width of the light pulse has already been femtosecond.The effect of nonlinearity and dispersion has been more complex.So we wish to figure out this problem by femtosecond soliton communication.In high-speed optical communication system,we will compress the distance between pulses to increase the information transfer rates.The interactions will be risen in the same time.Coupled femtosecond soliton communication is a modern communication technology which combines multiplexing and soliton transport.It will cause interference problems when we transmit multiplex signals.In this paper,we will study coupling femtosecond soliton and their interactions under different conditions.The main research method is the bilinear method based on symbolic computation.The major work of this paper is as follows:1.In wavelength division multiplexing(WDM)system,we transmit information by a variety of different carriers to increase capacity of the system coupling in one optical fiber.But it is difficult to solve the interference between the different wavelength pulse,when we improve the efficiency of multiplexing in WDM system.In this paper,it will be figured out by soliton communication.Then we will analyze the interactions caused by the too short distance between solitons.The transport model we study is N-coupled higher-order nonlinear Schr?dinger equation(N-CHNLSE)in WDM system.According to the model,we will derive the soliton solutions and observe the state of solitons in each channel.Next we will analyze the interactions between solitons by change the conditions of pulses.2.In the birefringent fibers,pulses will separated into two polarizations in the x and ydirections.Scientists have realized the multiplication of transmission capacity with this polarization multiplexing technology.The optical pulses propagates in the form of solitons which can overcome the problem ordinary optical pulse cannot keep a constant polarization.It can be achieved that optical pulse can keep not only stable strength and waveform,but also the state of polarization in the birefringent fibers.We will analyze the high-dimensional coupling femtosecond optical solitons in this paper.The transport model we study is(3+1)-dimensional coupled higher-order nonlinear Schr?dinger equation.According to the model,we will derive the bright and dark soliton solutions with bilinear method.In different planes we will observe the transmission evolution of soliton,and change the status of soliton to analyze the interactions between solitons.In addition,we get the(2+1)-dimensional coupled femtosecond optical solitons after degradation.3.On the basis of femtosecond optical pulses transmission model,we will explore the breathers and rogue waves which have been discovered in the field of optics in the last few years.The transport model we study is the extended multi-dimensional N-coupled higher-order nonlinear Schr?dinger equation.According to the model,we will derive(1+1),(2+1)and(3+1)dimensional coupling femtosecond optical breathers and rogue waves by bilinear method.Then we will analyze characters of the solutions in length,width,peak and so on to found that optical rogue waves has the extremely important application value in the communication system.