Chaos And Chaotic Synchronization In Erbium-Doped Fiber Ring Laser

Erbium-doped fiber ring laser is one of the important optic communication equipment, many researchers pay much attention to it for its special wave length and greatly potential application. It is the foundation for the application in optic communication and optic detection to study the chaos and chaotic synchronization in erbium-doped fiber ring laser, so it has important basic significance.In this dissertation, we mainly investigate the chaos and chaotic synchronization of erbium-doped fiber ring laser. At the same time, we study the application of the chaotic synchronization in secure communication. And we lay a strong emphasis on the realization of chaotic synchronization. The structure of this dissertation is organized as follows: Chapter 2 introduce the nonlinear dynamical characteristics of erbium-doped fiber ring laser. Chapter 3 research the chaotic synchronization. Chapter 4 give the result of application of chaotic synchronization in secure communication.In part one, we firstly introduce the basic theories of erbium-doped fiber ring laser, and then analyze the dynamic characteristic of erbium-doped fiber ring laser with pump and loss modulation from different aspects including attractor, time series, power spectra and Lyapunov exponent, which can find the chaotic region of the system. It shows that fiber laser can be in chaotic state with proper parameter for the relationship between maximum Lyapunov exponent and modulation coefficient, which can provide the numerical foundation for the chaotic synchronization.In part two, it is discussed for two types of chaotic synchronization in erbium-doped fiber ring laser with pump and loss modulation, which are chaotic driving synchronization and chaotic synchronization with delay feedback-injection. Firstly, we not only have realized the generalized chaotic synchronization between driving system and driven system of erbium-doped fiber ring laser, but also acute chaotic synchronization of the two identical driven systems. We give the condition of the chaotic synchronization with pump modulation and loss modulation by calculating the relationship between the maximum conditional Lyapunov exponent and the driving stiffness, Also, the influence of parameter mismatches on chaos synchronization is investigated. Secondly, we have realized the chaotic synchronization of two erbium-doped fiber ring laser using delay feedback-injection scheme. Numerical result shows that the two erbium-doped fiber ring lasers can be well synchronized if the strengths of delay feedback and injection are suitable, they still reach good synchronization, even though the effect of the gauss noises is considered,. Also, we have found the method delay feedback-injection is of robustness, which is the basis for its application in practice.In part three, we go further into the application of chaotic synchronization. The optic secure communication is realized by using chaotic synchronization of chaotic erbium-doped fiber ring laser based on chaotic driving method, also we realized the encryption and decryption of the analog and digital signals by chaotic conceal and chaotic modulation, the numerical result is heart stirring.