Self-Similar Parabolic Pulses in a Varying Nonlinearity Fibre

We theoretically analyse the existence and propagation properties of self-similar parabolic pulse in varying nonlinearity fibre with an exponential nonlinearity profile. As well as the normal dispersion decreasing fibre with a hyperbolic dispersion profile, the varying nonlinearity fibre is equivalent to the fibre amplifier, which can generate the self-similar parabolic pulses with strictly linear chip. In addition, the influence of the initial pulse energy, pulse width, the nonlinearity coefficients and the second-order dispersion on the self-similar region, the best self-similar region for different initial pulses and fibre parameters are investigated numerically and analytically. The results indicate that the self-similar parabolic pulses can be generated in varying nonlinearity fibre, the best initial pulses and fibre parameters are helpful for obtaining the ideal self-similar parabolic pulses.