The Studies Of Coupled Dark Soliton Pairs In Birefringence Fiber

In practice, all fibers exhibit some modal birefringence because of unintentional variations in the core shape and anisotropic stresses along the fiber length. Such fibers exhibit nearly constant birefringence along their entire length. This kind of birefringence is called linear birefringence. When the nonlinear effects in optical fibers become important, a sufficiently intense optical field can induce nonlinear birefringence whose magnitude is intensity dependent. Solitons in birefringence fiber are divided into two components such solitary waves are referred to as vector solitons to emphasize the fact that an input pulse maintains not only its intensity profile but also its state of polarization even when it is along with different principal axes of the fiber. In this case we can improve communication capacity.In linear polarization fibers, we consider that solitons with the same frequency along with different principal axes. These axes are called slow and fast axes based on the speed at which light polarized along them travels inside the fiber, which can be described by coupled Ginzburg-Landau equations. Then we make some calculation and simulation about that. Than We find exact chirped dark-dark soliton-like solution by use the suitable ansatz.Below is the main content of the thesis:(1) We illustrate details of the coupled Ginzburg-Landau equations and FFT algorithm.(2) The Fast Fourier Transform Algorithm are used respectively numerically to analyse soliton pairs such as chirped bright—dark and chirped dark—dark which are propagating in the linear polarization fiber system.(3) We use the suitable ansatz to find exact chirped dark-dark soliton-like solution of High-Birefringence Fibers and numerically analysis.