Analytic study on amplification of solitons in inhomogeneous optical fibers

Abstract

An analytic study on soliton amplification in inhomogeneous optical fibers is presented in this paper. By use of the Hirota method, the bilinear forms for the nonlinear Schrödinger equation, which describes the soliton propagation in inhomogeneous optical fibers, are obtained. The analytic soliton solutions are derived with symbolic computation. According to the solution obtained, the solitons are amplified without the pedestals, and the technique permit high-quality amplification of solitons, which to our knowledge has not been reported before. The physical effects affecting soliton amplification are discussed. The gain of the amplifier, the soliton velocity and phase can be adjusted with two arbitrary parameters. The influences of group-velocity dispersion and Kerr nonlinearity on soliton amplification are studied. With the different values of group-velocity dispersion and Kerr nonlinearity, amplification of solitons in inhomogeneous optical fibers can be controlled. The results of this paper provide a simple and efficient approach to amplify solitons in the communication systems.