The journal article titled “Parabolic and rectangular self-similar evolution in saturable media” was published in “Romanian Reports in Physics” by ITU Department of Mathematics Engineering members Prof. Dr. İlkay Bakırtaş,  Prof. Dr. Nalan Antar  et al.

Many theoretical and experimental studies have recently focused on the generation of optical solitons in optical fibers. Unlike optical solitons, similaritons can tolerate strong nonlinearity without wave breaking. The accumulated phase of the pulse is successfully linearized by second-order dispersion, which allows the spectral bandwidth to be increased without the pulse becoming unstable. A new analytical solution of nonlinear Schrödinger equation that is describing the propagation of parabolic similaritons in fiber amplifiers, taking into account the influence of saturated gain is investigated before but the effects of the saturable nonlinearity on pulse shape have not been investigated in all studies conducted to date. In this paper, we presented numerical results regarding the pulse shape evolution towards parabolic and rectangular profiles depending on the external potential and nonlinearity and saturation parameters.