Characteristics Of Self-similar Pulse In Optic Fiber

Parabolic pulse, generated in a dispersion-decreasing optical fiber or fiber amplifier with normal group-velocity dispersion, has become a topic of growing interest owing to its attractive characteristics, such as resistance to optical wave breaking, self-similarity in shape, and enhanced chirp linearity. In particular, the asymptotic pulse's features are independent of the incident pulse shape, and all of the incident pulse energy contributes to the output parabolic pulse. Moreover, its linear chirp facilitates efficient temporal compression. These attractive features lead parabolic pulse to a wide-range practical significance, such as stimulated Raman scattering, optical wave collapse, and self-written waveguides. Recent attention has been riveted on the self-similar propagation of parabolic optical pulses in an optical fiber amplifier and a decreasing-dispersion optical fiber. So study on the pulse self-similarity has a wide-range practical significance on many research field.The generation of self-similar pulse in a dispersion-decreasing fiber with normal group-velocity dispersion (ND-DDF) is investigated theoretically in this dissertation. According to the nonlinear schrodinger equation (NLSE), a self-similar solution is given out. Furthermore, the influence of different initial pulse' parameters and high-order dispersion on the generation of self-similar pulse are analyzed. The dissertation consists of 7 chapters. The first one is to briefly introduce the PCF concepts, and the second one presents the basic theory of the work. Chapter 3, 4, 5 and 6 are the introduction of the main work of the author. Chapter 7 makes a conclusion of the whole work and shows some prospective views. The main research results are summarized as follows.Chapter 1 is to briefly introduce the self-similarity of optical pulse, including their developing background, their present researching states, and prospective applications.Chapter 2 presents the theory of pulse propagating equation in optical fiber.Chapter 3 proposes self-similar solution of optical pulse in normal-dispersion fiber amplifiers. Chapters 4 study the generation principle of parabolic pulse in a dispersion-decreasing fiber with normal group-velocity dispersion, and analyze the influence of different initial parameters to self-similar pulse generation, advancing the scheme of obtaining high-quality self-similar pulse.Chapter 5 focuses on the influence of high- dispersion to parabolic pulse, which leads parabolic pulse to become abnormal. Besides, the high- quality compressing pulse can still be obtained, with a FWHM about 100fs.Chapter 6 research on the interaction between Parabolic Pulses in a Dispersion-decreasing FiberChapter 7 includes the conclusions and prospective views.