Solitons are a ubiquitous phenomena in nature applicable to a large class of solitary wave propagation effects that can be observed in most branches of nonlinear science, from fluid dynamics and biology to plasma physics and photonics.
In Optics, they are characterized by a self-reinforcing and shape preserving wave packet resulting from the interplay between the linear and nonlinear effects. In the case of nonlinear optics, the soliton is attributed to the balance between anomalous (normal) dispersion and self-focusing (Defocusing) nonlinearity.
Dissipative solitons in photonics can be defined as localized formations of an electromagnetic field that are balanced through the energy exchange with the environment in the presence of nonlinearity, dispersion, and/ or diffraction.