Dynamics of chirped similaritons on a continuous-wave background in weakly birefringent optical fibers

New coupled self-similar localized waves on a continuous-wave background taking the form of chirped bright-W-shaped similaritons are identified for the first time in an inhomogeneous weakly birefringent fiber wherein the light transmission is modeled by a system of two coherently coupled nonlinear Schrödinger equations with distributed coefficients. It is found that these similariton waveforms occur in the third-order defocussing nonlinearity regime. Two different types of chirped kink–antikink similaritons are also obtained in the self-focusing nonlinearity regime. As important property is that the similariton waveforms display a quadratic phase structure, thus implying that these nonlinear wavepackets have a linear frequency chirp that makes them potentially useful for the achievement of effective pulse compression and amplification. Evolutional behaviors of the obtained optical similaritons are discussed under different profiles of the system distribution parameters. The outcomes demonstrate that the evolution dynamics of similariton pairs can be essentially controlled by designing appropriate dispersion, nonlinearity and gain/loss parameters.