Amplification, reshaping, fission and annihilation of optical solitons in dispersion-decreasing fiber

Amplification, reshaping, fission and annihilation of optical solitons can be applied in fiber lasers, all-optical switching devices and optical communications. In this paper, for the variable coefficient high-order nonlinear Schrodinger equation, analytic two- and three-soliton solutions are derived by the Hirota bilinear method. Optical solitons propagation in the dispersion-decreasing fibers is investigated theoretically. The influence of corresponding parameters is discussed based on obtained solutions. By choosing properly parameters, optical solitons are amplified and reshaped stably in a long distance. Besides, the number of amplified solitons can be chosen as required. Moreover, a novel phenomenon that three solitons can split into four solitons or merge into two solitons has been proposed. Results may be helpful to realize the amplification, reshaping, fission and annihilation of solitons, and will be valuable to the applications of optical amplifier, all-optical switching and optical self-routing.