In this paper a unique analysis of solitary waves corresponding to the solutions of the non-linear cubicquintic Schr6dinger equation for optical fibers is performed. These results imply that for an intensitysquared dependent refractive index, the behavior of the solitary waves is at most quasi-soliton. In our context there is not soliton behavior so that the existence of Raman solitons is not possible. However, under certain conditions it is reasonable to expect the existence of Raman quasi-solitons in the anomalous- dispersion regime.The mathematical aspects involved are emphasized because the theoretical research is very important in the context of non-linear optics to clarify various, often confusing ideas derived from certain experimental works.